B...

BACP      Bandwidth Allocation Control Protocol
BAK       Binary Adaptation Kit [Microsoft]
.BAK      Backup (file name extension)
BAL       Basic Assembly Language
BALUN     Balanced Unbalanced (device)
BAM       Boyan Action Module
BARTS     Bell Atlantic Regional Timesharing
.BAS      Basic Language (file name extension)
BASH      Bourne Again Shell [Unix]
BASIC     Beginner's All-purpose Symbolic Instruction Code
BASM      Built-In Assembler
BAT       Block Address Translation
.BAT      Batch Processing (file name extension)
BBS       Bulletin Board System
BCC       Block Check Character
BCC:      Blind Carbon Copy
BCD       Binary Coded Decimal
B-CHANNEL Bearer Channel
BCL       Batch Command Language
BCN       Beacon
BCP       Best Current Practice + Bulk Copy Program
BCPL      Basic Computer Programming Language
BCR       Byte Count Register
BCS       Bar Code Sorter
BDA       Bios Data Area
BDC       Backup Domain Controller
BDE       Borland Database Engine [Borland]
BDLS      Bidirectional Loop Switching
BDOS      Basic Disk Operating System
BDR       Bus Device Request
BDSL      Broadband ADSL
BE        Below or Equal
BECN      Backward Explicit Congestion Notification
BEDO      Burst Extended Data Out
BEL       Bell
BELLCORE  Bell Communications Research
BER       Basic Encoding Rules + Bit Error Rate
BERT      Bit Error Rate Test/Tester
BF        Bad Flag
B/F       Background/Foreground
BFF       Binary File Format [IBM]
BFT       Binary File Transfer
BFTP      Batch FTP
BGA       Ball Grid Array
BGCOLOR   Background Color [HTML]
BGE       Branch if Greater or Equal
.BGI      Borland Graphic Interface (file name extension)
BGP       Border Gateway Protocol
BGT       Branch if Greater Than
BHI       Branch if Higher
BHIS      Branch if Higher or Same
BI        Binary Input
.BIB      Bibliography (file name extension)
BiDi      Bi-Directional
BIFET     Bipolar Field Effect Transistor
BIFF      Binary Interchange File Format
BIM       Beginning of Information Marker
.BIN      Binary (file name extension)
BINAC   * Binary Automatic Computer
BIND      Berkeley Internet Name Domain
BINHEX    Binary Hexadecimal
BIOS      Basic Input/Output System
BIS       Business Information System
BISDN     Broadband Integrated Services Digital Network
BIST      Built-In Self-Test
BiSYNC    (See BSYNC)
BIT       Binary Digit
BITNET    Because It's Time Network
BITNIC    Bitnet Network Information Center
BIU       Bus Interface Unit
BIX       Byte Information Exchange (BBS)
BIZ.      Business [USENET Newsgroup Category]
.BK!      Backup (file name extension) [WordPerfect]
.B~K      Backup (file name extension)
BKSP      Backspace
BL        Backlit + Bit Line
BLAST     Blocked Asynchronous Transmission (protocol)
          [Communications Research Group]
.BLD      BASIC Bload Graphics (file name extension)
BLE       Branch if Less or Equal
BLER      Block Error
BLK       Block
BLMC      Buried Logic Macrocell
BLOB      Binary Large Object
BLOS      Branch if Lower Or Same
BMI       Branch if Minus
BMIC      BusMaster Interface Controller [Intel]
BMP       Basic Mapping Support + Batch Message Processing Program
.BMP      Bitmap (file name extension) [Paintbrush Format]
BNC       Bayonet Neill-Concelman (connector used with
          coaxial cable invented by Mr. Neill-Concelman)
BNE       Branch if Not Equal
BNF       Backus-Naur Form (also Backus-Normal Form) [developed by
          John Backus and Peter Naur]
BNS       Backbone Network Service
BO        Binary Output
BoB       Break-out Box
BOC       Basic Operator Console
BOF       Beginning Of File
BOM       Beginning Of Message
BOND      Bandwidth On Demand
BOOTP     Bootstrap Protocol [Internet]
BOPS      Billion Operations Per Second
BORPQU    Borland Pro Quattro
BORQU     Borland Quattro
BOS       Basic Operating System
BOT       Beginning Of Table + Beginning of Tape + Robot
BP        Base Pointer
BPB       BIOS Parameter Block
BPDU      Bridge Protocol Data Unit
BPI       Bits Per Inch
BPL       Branch if Plus
BPS       Bits Per Second + Bytes Per Second
BR        Bad Register
BRGC      Binary Reflected Gray Code
BRI       Basic Rate Interface + Brain Response Interface
BS        Backspace
BSAM      Basic Sequential Access Method
BSC       Binary Synchronous Communication
.BSC      Boyan Script (file name extension) [Boyan Communications]
BSCS      Bachelor of Science (Degree) in Computer Science
BSD       Berkely Software/Standard Distribution
BSF       Bit Scan Forward
BSI       British Standards Institute
BSP       Bulk Synchronous Parallelism
BSR       Bit Scan Reverse
BSS       Block Started by Symbol
BSV       BASIC Bsave Graphics (file name extension)
BSY       Busy
BSYNC     Binary Synchronous Communications (protocol)
BT        Bit Test
BTAM      Basic Telecommunications Access Method [IBM]
BTB       Branch Target Buffer
BTC       Bit Test and Complement
BTOA      Binary To ASCII
BTP       Batch Transfer Program
BTR       Bit Test and Reset
BTS       Bit Test and Set
BU        Branch Unit
BUBL      Bulletin Board for Libraries [Janet]
BUF       Buffer
BUS       Broadcast and Unknown Server
BVH       Base Video Handler
BWM       Block-Write Mode
B2X       Binary To Hexadecimal [REXX]
BYTE      Binary Element String

C...

C         C Programming Language
.C        C source code (file name extension) [C]
CA        Collision  Avoidance
.CAB      Cabinet (file name extension) [Microsoft]
CAD       Computer Aided Design
CADD      Computer Aided Design and Drafting
CADE      Client/server Application Development Environment
CAE       Client Application Enabler +
          Common Applications Environment + Computer Aided Engineering
CAEX      Computer Aided Exploration
CAG       Column Address Generator
CAI       Computer Aided Instruction
CAL       Calendar + Computer Aided Learning
CALS      Computer-Aided Acquisition in Logistic Support
CAM       Common Access Method + Computer Aided Manufacturing +
          Contents Addressable Memory
CAN       Cancel
CAP       Carrierless Amplitude and Phase-Modulation +
          Central Arbitration Point +
          Communication Application Platform +
          Competitive Access Provider +
          Computer Aided Publishing
.CAP      Capture (file name extension)
CAPD      Computing To Assist Persons With Disabilities [Johns
          Hopkins University]
CAPS      Capitals (Upper Case Letters) +
          Cassette Programming System
CARL      Colorado Alliance of Research Libraries [Internet]
CAS       Column Address Select +
          Communications Application Specification +
          Computer Aided Styling
CASE      Computer Aided Software Engineering
CASL      Crosstalk Application Scripting Language [DCA]
CASS      Computer Assisted Search Service
CASSIS    Classified and Search Support Information System
CAT       Computer Adaptive Test + Computer Aided Testing +
          Computer Aided Tomography +
          Computer Aided Transcription + Concatenate
.CAT      Catalog (file name extension)
CATS      Computer Assisted Training System
CAT SCAN  Computerized Axial Tomography Scan
CATV      Community Antenna Television (this was the original
          name for what is now known as Cable TV)
CAU       Controlled Access Unit
CAV       Constant Angular Velocity
CBC       Cipher Block Chaining
CBCR      Channel Byte Count Register
CBDS      Connectionless Broadband Data Service
CBEMA     Computer and Business Equipment
          Manufacturers Association
CBGA      Ceramic Ball Grid Array
CBI       Computer Based Instruction
CBL       Computer Based Learning
.CBL      COBOL source code (file name extension)
CBMS      Computer-Based Mail System
CBR       Case Based Reasoning + Constant Bit Rate
CBT       Computer Based Training
CBW       Convert Byte to Word
CBX       Computer-Controlled Branch Exchange
CC        Cluster Controller
CC:       Carbon Copy
CCD       Charged-Coupled Device
CCFT      Cold Cathode Fluorescent Tube
CCI       Common Client Interface
CCITT     Comite Consultatif International Telegraphique et Telephonique/
          Consultative Committee for International Telegraph and Telephone
CCL       Connection/Cursor Control Language
CCP       Console Command Processor
CCS       Common Command Set + Common Communications Services +
          Common Communications Support +
          Continuous Composite Servo
.CCS      Color Calibration System (file name extension)
CCSD      Cellular Circuit-Switched Data
CD        Carrier Detect + Change Directory +
          Collision Detection + Color Display + Compact Disk
C/D       Control Data
C2D       Character To Decimal [REXX]
CDA       Compound Document Architecture [DEC]
CDC       Control Data Corporation
CD_CHRDY  Card Channel Ready [IBM]
CD-DA     Compact Disk -Digital Audio
CDDI      Copper Distributed Data Interface
CDE       Common Desktop Environment + Complex Data Entry
CD-E      Compact Disk - Erasable
CDF       Channel Definition Format
.CDF      Comma Delimited Format (file name extension)
CDFS      Compact Disc File System [Microsoft]
CD+G      Compact Disk plus Graphics
CD-I      Compact Disk - Interactive
CDIA      Certified Document Imaging Architect
CDL       Computer Design Language
CDMA      Code Division Multiple Access
CDMF      Commercial Data Masking Facility [IBM]
CD-MO     Compact Disk - Magneto Optical
CDOS      Concurrent Disk Operating System
CDPD      Cellular Digital Packet Data
CDR       Call Detail Record + Call Detail Recording
CD-R      Compact Disk - Recordable
CD-RDx    Compact Disk - Read Only Memory Data Exchange Standard
CDRL      Contract Data Requirements List
CD-ROM    Compact Disk - Read Only Memory
CD-RTOS   Compact Disk - Real Time Operating System
CD-RW     Compact Disk - Re-Writable
CDS       Current Directory Structure
CDSA      Common Data Security Architecture
.CDT      Corel Draw Template (file name extension)
CD-V      Compact Disk - Video
CD-WO     Compact Disk - Write Once
.CDX      Compound Index (file name extension) [Fox Pro]
CD-XA     Compact Disk - Extended Architecture
CE        Cache Enable + Chip Enable + Collision Elimination +
          Convert Enable
CEG       Continuous Edge Graphics
CEI       Conducted Electromagnetic Interference
CELP      Card Edge Low Profile (socket) [Intel]
CEMS      Constituent Electronic Mail System
CEOP      Conditional End Of Page
CER       Canonical Encoding Rules
CERN      The European Particle Physics Laboratory (initials
          originally from Conseil European pour la Recherche Nucleaire)
CERT      Computer Emergency Response Team
CFB       Cipher Feedback + Configurable Function Block
.CFG      Configuration (file name extension)
CFM       Code Fragment Manager [Macintosh]
CFR       Computerized Facial Recognition
CFS       Caching/Common File System
CFV       Call For Votes [Bitnet]
CG        Control Gate
CGA       Color Graphics Adapter
CGE       Common Graphics Environment
CGI       Common Gateway Interface + Computer Generated Images +
          Computer Graphics Interface
.CGM      Computer Graphics Metafile (file name extension) +
          Graph (file name extension) [Lotus 1-2-3] [LDC]
CHAP      Challenge-Handshake Authentication Protocol
CHAR      Character
CHAT      Conversational Hypertext Access Technology [Internet]
CHCK      Channel Check
CHCP      Change Code Page
CHDIR     Change Directory
CHFN      Change Finger [Unix]
CHGRP     Change Group
.CHK      CHKDSK (file name extension)
CHKDSK    Check Disk
CHMOD     Change Mode
CHOWN     Change Owner
CHP       Chapter
CHR       Character
CHRP      Common Hardware Reference Platform
CHS       Cylinder Head Sector
CI        Component Interface
CIA       Current Instruction Address
CIAC      Computer Incident Advisory Capability
CICS/VS   Customer Information Control System/
          Virtual Storage [IBM]
CID       Charge-Injection Device +
          Configuration/Installation/Distribution
CIDR      Classless Inter-Domain Routing
CIF       Common Interchange/Intermediate Format +
          Crystallographic Information File +
          Customer Information Feed
CIFS      Common Internet File System
CIM       Common Information Model +
          CompuServe Information Manager +
          Computer Integrated Manufacturing
CIO       Chief Information Officer
CIOCS     Communication Input/Output Control System
CIP       Command Interface Port
CIR       Committed Information Rate
CIRC      Circular Reference +
          Cross-Interleaved Reed-Solomon Code
CIS       Card Information Structure + Client Information System +
          CompuServe Information Service +
          Computer Information Systems + Contact Image Sensor +
          Customer Information System
CISC      Complex Instruction Set Computer
CIT       Computer-Integrated Telephony
CIVR      Computer and Interactive Voice Response
CIX       Commercial Internet Exchange +
          Compulink Information Exchange
CJLI      Command Job Language Interpreter
CKD       Count Key Data (device)
CLAR      Channel Local Address Register
CLASS     Client Access to Systems and Services +
          Cooperative Library Agency for Systems and Services +
          Custom Local-Area Signaling Services
CLC       Clear Carry Flag
CLD       Clear Direction Flag
CLI       Call-Level Interface + Clear Interrupt Flag +
          Client Library Interface + Command Line Interface
CLIB      C Library
CLID      Calling Line Identification
CLIST     Command List
CLK       Clock
CLNP      Connectionless Network Protocol
CLOS      Common Lisp Object System
CLP       Cell Loss Priority + Constraint Logic Programming
.CLP      Clipboard (file name extension) [Windows]
CLS       Clear Screen
CLTP      Connectionless Transport Protocol
CLTS      Clear Task Switch Flag
CLUI      Command Line User Interface
CLUT      Color Look-Up Table
CLV       Constant Linear Velocity
CM        Centimeter + Control Mark + Corrective Maintenance
CMA       Concert Multi-thread Architecture
CMC       Common Mail Calls + Common Messaging Calls +
          Communication Management Configuration +
          Complement Carry Flag +
          Computer-Mediated Communication [Internet]
CMD       Circuit Mode Data
.CMD      Command (file name extension)
CMF       Creative Music Format
CNIDR     Clearinghouse for Network Information and
          Discovery and Retrieval [Internet]
CMIP      Common Management Information Protocol
CMIS      Common Management Information Services/System
CML       Conceptual Modelling Language +
          Computer Managed Learning + Current Mode Logic
CMM       Capability Maturity Model
CMMS      Computerized Maintenance Management Software
CMMU      Cache/Memory Management Unit [Motorola]
CMOS      Complementary Metal-Oxide Semiconductor
CMOV      Conditional Move
CMP       Compare + Computer
CMPS      Compare word String
CMS       Code Management System + Compiler Monitor System +
          Conversation Monitor System
CMVC      Configuration Management Version Control [IBM]
CMW       Compartmented Mode Workstation
CMY       Cyan-Magenta-Yellow (color model)
CMYK      Cyan-Magenta-Yellow-Black (color model)
CNA       Certified NetWare Administrator [Novell]
CNAPS     Co-Processing Node Architecture for Parallel Systems
CNC       Computerized Numerical Control
CNE       Certified NetWare Engineer
.CNF      Configuration (file name extension)
CNG       Calling (tone)
CNI       Certified Novell Instructor [Novell]
CNIDR     Clearinghouse for Networked Information and Retrieval
CNN       Composite Network Node
CNR       Carier to Noise Ratio
CNSS      Core Nodal Switching Subsystem [Internet]
.CNT      Contents (file name extension)
CNV       Conventional (pertaining to Memory)
CNVT      Convert
CNX       Certified Network Expert
CO        Central Office + Command Output + Convert Out
COAX      Coaxial Cable
COB       Chip-On-Board
.COB      COBOL source code (file name extension)
COBOL     Common Business-oriented Language (See HLL)
.COD      Code List (file name extension)
CODASYL * Conference on Data System Languages (Group that
          designed COBOL)
CODE      Client-Server Open Development Environment
CODEC     Coder/Decoder + Compression/Decompression
COEM      Commercial Original Equipment Manufacturer
COFF      Common Object File Format [Unix]
COGO      Coordinate Geometry (Programming Language)
COL       Collision + Computer Oriented Language
COLD      Computer Output to Laser Disk
COLL      Collision
COM       Common Object Model [Microsoft] +
          Computer Output Microfilm
.COM      Command (file name extension) +
          Commercial Business (Domain Name0 [Internet]
COM1      First serial Port (asynchronous port)
COM2      Second serial Port
COM3      Third serial Port
COM4      Fourth serial Port
COMDEX    Computer Dealers Exposition
COMET     Cornell Macintosh Terminal Emulator
COMP      Compare + Communications
COMP.     Computers [USENET Newsgroup Category]
COMSAT    Communications Satellite Corporation
CON       Console (includes Keyboard and Screen)
COND      Condition
CONFIG    Configuration
CONS      Connection-Oriented Network Service
CONTONE   Continuous Tone
COPICS    Communications Oriented Production Information
          and Control System [IBM]
CORBA     Common Object Request Broker Architecture
CoREN     Corporation for Research and Enterprise Network
COS       Compatible Operating System
COSE      Combined Office Standard Environment +
          Common Open Software/Systems Environment
COSMIC    Computer Software Management and Information
          Center [NASA]
COSMOS    Computer System for Mainframe Operations
COSS      Common Object Services Specification
COTS      Commercial Off-The-Shelf
CP        Copy Protected
CPA       Certified Public Accountant
CPC       Constant Point Calculation
CPCS      Check Processing Control System [IBM]
CPE       Central Processing Element +
          Customer Premises Equipment +
          Customer Provided Equipment
.CPE      Cover Page (file name extension)
CPG       Clock Pulse Generator
CPI       Characters Per Inch + Clock Per Instruction +
          Common Programming Interface [IBM]
.CPI      Code Page Information (file name extension) [MS-DOS]
CPI-C     Common Programming Interface for Communications [IBM]
CPIO      Copy In and Out [Unix]
CPL       Current Privilege Level
.CPL      Control Panel (file name extension)
CPM       Critical Path Method
CP/M      Control Program for Microcomputers [Digital Research]
CPS       Characters Per Second + Cycles Per Second
CPT       Command Pass Through
CPU       Central Processing Unit
CR        Carriage Return
CRAM      Cyberspatial Reality Advancement Movement
CRAYON    Create Your Own Newspaper
CRC       Cyclic Redundancy Check
.CRD      Cardfile (file name extension) +
          Chord (music file name extension)
CREN      Computer Research Education Network +
          Corporation for Research and Education Networking
CRF       Cable Retransmission Facility + Cross Reference File
CRI       Color Reproduction Indices
CR/LF     Carriage Return/Line Feed
CROM      Control Read Only Memory
CRT       Cathode Ray Tube
CRTC      CRT Controller
CS        Chip Select + Clear to Send + Code Segment
C/S       Client/Server
CSA       Calendaring and Scheduling API [IBM]
CSAR      Channel System Address Register
CSCW      Computer Supported Cooperative Work
CSD       Circuit-Switched Data +
          Computer Services Department +
          Corrective Service Diskette [IBM]
CSDS      Circuit Switched Data Service
CSE       Certified System Engineer
CSFI      Communication Subsystem For Interconnection
CSG       Constructive Solid Geometry +
          Consulting Services Group [Lotus]
CSI       Command Sequence Introducer + CompuServe Incorporated
CSID      Call Subscriber ID
CSL       Computer Sensitive Language
CSLIP     Compressed Serial Line Interface Protocol [Internet]
CSM       Code Set Map (file) + Communications Services Manager
CSMA/CA   Carrier Sense Multiple Access/with Collision Avoidance
CSMA/CD   Carrier Sense Multiple Access/with Collision Detection
CSMS      Customer Support Management System
CSN       Card-Select Number
CSNET     Computer Science Network
CSO       Central Services Organization
CSP       Certified Systems Professional +
          Commercial Subroutine Package +
          CompuCom Speed Protocol [CompuCom] +
          Communicating Sequential Processes +
          Cross System Product [IBM]
CSPDN     Circuit Switched Public Data Network
CSS     * Continuous System Simulator (Language)
CSS       Cascading Style Sheets [Microsoft] +
          Contact Start-Stop
CSSM      Client-Server Systems Management [IBM]
CS/SS     Card Service/Socket Service
CSTA      Computer-Supported Telephony Applications
CSU       Channel Service Unit
CSV       Circuit-Switched Voice +
          Comma-Separated Value/Variable +
          Common Services Verbs (interface) [Microsoft]
C&T       Chips and Technologies
CTB       Cipher Type Byte
CTC       Channel To Channel
CTCP      Client-To-Client Protocol
CTI       Computer-Telephony Integration
CTOS      Computerized Tomography Operating System +
          Convergent Technologies Operating System
CTPA      Coax-to-Twisted-Pair Adapter
CTRCO   * Calculating,Tabulating,Recording Company (The name of
          this company was changed to "International Business
          Machines" by Thomas J. Watson, Sr.)
CTRL      Control
CTS       Clear To Send + Customer Telephone System
CTSS    * Compatible Time Sharing System
CUA       Common User Access [IBM]
CUB       Cursor Backward
CUD       Cursor Down
CUE       Custom Updates and Extras (card) [Egghead Software]
CUF       Cursor Forward
CUI       Character-Oriented User Interface +
          Common User Interface [IBM]
CUP       Cursor Position
CUPID     Completely Universal Processor I/O Design [AST]
.CUR      Cursor (file name extension)
CUSIP     Committee for Uniform Security Identification
          Procedures [U.S. Treasury]
CUT       Control Unit Terminal
CUTE      Clarkston University Terminal Emulator
CUU       Cursor Up
CVF       Compressed Volume File
CVGA      Color Video Graphics Array
CVIA      Computer Virus Industry Association
CVT       Convert
CVW       CodeView for Windows
CWD       Convert Word to Double Word +
          Change Working Directory [Internet]
CWIS      Campus Wide Information Service/System [Internet] +
          Community Wide Information Service/System [Internet]
C2X       Character To Hexadecimal [REXX]
CYL       Cylinder
CYMK      Cyan-Yellow-Magenta-Black (color model)

D...

D/A       Digital to Analog
DAA       Data Access Arrangement +
          Decimal Adjust for Addition
DAC       Data Acquisition and Control +
          Digital to Analog Converter +
          Dual Attachment Concentrator
DAD       Desktop Application Director [Borland]
DAI       Distributed Artificial Intelligence
DAL       Data Access Language [Apple Computer] +
          Disk Access Lockout
DAM       Data Acquisition and Monitoring
DAMPS     Digital AMPS
DAO       Data Access Object [Microsoft]
DAP       Data Access Protocol [DEC] +
          Developer Assistance Program
DAPIE     Developers Application Programming Interface Extensions
DARI      Database Application Remote Interface [IBM]
DARMS     Digital Alternate Realization of Musical Symbols
DART      Digital Audio Reconstruction Technology
DAS       Decimal Adjust for Subtraction +
          Dual-Attached Station
DASD      Direct Access Storage Device [IBM]
DAT       Digital Audio Tape + Disk Array Technology
.DAT      Data (file name extension)
DATACOM   Data Communications
DAV       Digital Audio-Video
DAVIC     Digital Audio-Visual Council
dB        Decibel
DB        Data Base + Data Buffer
dBA       Adjusted Decibel
DBCS      Delivery Bar Code Sorter + Double-Byte Character Set
.DBF      Database (file name extension)
DBIS      Dun & Bradstreet Information Services
DBM       Data Base Manager
DBMS      Data Base Management System
DBS       Data Base Server
DBV       Digital Broadcast Video
DB2       Database 2
DC        Data Collection + Data Communication + Data Control +
          Device Control + Direct Current
D2C       Decimal To Character [REXX]
DCA       Digital Communications Associates +
          Document Content Architecture [IBM]
DCAF      Distributed Console Access Facility [IBM]
DCAM      Direct Chip Attach Module
DCB       Device Control Block + Disk Coprocessor Board [Novell]
DCC       Digital Command Control + Digital Compact Cassette +
          Direct Cable/Client Connection + Display Combination Code
DCD       Data Carrier Detect
DCE       Data Circuit-Terminating Equipment +
          Data Communications Equipment +
          Distributed Computing Environment [OSF] +
          Distributed Computing Equipment
DCED      Distributed Computing Environment Daemon
DCF       Data Communication Facility [IBM] +
          Data Compression Facility +
          Data Count Field [IBM] +
          Driver Configuration File [Lotus]
D-CHANNEL Data Channel
DCI       Display Control Interface
DCL       Data Control Language + Declaration +
          DEC Command Language [DEC] +
          Device Clear + Digital Control Logic +
          Digital Command Language [Digital]
DCOM      Distributed Component Object Model
DCP       Digital Light Processing [TI]
DCS       Data Collection System + Data Control System +
          Desktop Color Separation + Distributed Control System
DCT       Discrete Cosine Transform
.DCT      Dictionary (file name extension)
DCU       Data-Cache Unit
DD        Day + Digital Display + Double Density
DDA       Distributed Data Access + Domain-Defined Attribute
DDB       Device Dependent Bitmap + Device Descriptor Block
DDC       Digital Data Channel [VESA] + Display Data Channel
DDCMP     Digital Data Communications Message Protocol [DEC]
DDC1      Display Data Channel One
DDCS      Distributed Database Connection Services [IBM]
DDD       Data Definition Language + Direct Distance Dialing
DDE       Direct Data Entry + Dynamic Data Exchange [Microsoft]
DDEML     Dynamic Data Exchange Manager Library [Microsoft]
DDF       Display Data Channel + Dynamic Data Formatting [IBM]
DDI       Device Driver Interface + Direct Dial In
DDK       Device Driver Kit [Microsoft Windows]
DDL       Data Definition Language + Data Description Language
DDM       Distributed Data Management
DDN       Defense Data Network
DDNS      Dynamic Domain Naming System
DDP       Distributed Data Processing
DDS       Digital Dataphone Service [AT&T] + Design Data Sheet +
          Digital Data Storage + Distributed Database Services
DDX       Digital Data Exchange
DE        Device End
DEC       Decrement + Device Clear + Digital Equipment Corporation
DECNET    Digital Equipment Corporation Networking (protocol)
DEF       Desktop Functional Equivalent [Compaq]
.DEF      Definitions + Defaults (file name extensions)
DEFRAG    Defragment
DEK       Data Encryption Key
DEL       Delete
DELSTR    Delete String [REXX]
.DEM      Demonstration (file name extension)
DEN       Document Enabled Networking [Novell-Xerox]
DER       Distinguished Encoding Rules
DES       Data Encryption Standard + Data Entry Sheet
.DES      Description (file name extension)
DET       Device Execute Trigger
DEV       Device
DF        Data Field + Destination Field + Device Flag +
          Double Flag
DFC       Data Flow Control
DFM       Design For Manufacturability [IBM]
DFS       Distributed File System
DFSMS     Data Facility Storage Management Subsystem [IBM]
DFT       Design For Testability + Diagnostic Function Test +
          Discrete Fourier Transform +
          Distributed Function Terminal
DFU       Data File Utility
DGIS      Direct Graphics Interface Standard
DHCP      Dynamic Host Configuration Protocol
DHL       Dynamic Head Loading
.DHP      Dr. Halo PIC (file name extension)
DHTML     Dynamic HTML
DI        Data In + Destination Index
DIA       Document Interchange Architecture [IBM]
DIB       Device Independent Bitmap +
          Directory Information Base +
          Dual Independent Bus [Intel]
DIBOL     DEC Business Oriented Language
.DIC      Dictionary (file name extension)
DID       Direct Inward Dialing
DIDS      Distributed Intrusion Detection System
DIF       Data Interchange Format
DIFFSENS  Differential Sense
DIIP      Direct Interrupt Identification Port
DIMM      Dual In-Line Memory Module
DIN       Deutsche Industrie Norm (German equivalent of EIA)
DIO       Data Input-Output
DIP       Dialup Internet Protocol [Internet] +
          Digital Imaging Processing +
          Dual In-line Package + Dual In-line Pin
DIR       Directory (file)
DIS       Draft International Standard +
          Dynamic Impedance Stabilization [CompuCom]
DISA      Data Interchange Standards Association
DISP      Displacement (offset)
DIT       Directory Information Tree
DIV       Divide
DIVE      Direct Interface Video Extension [OS/2 Warp]
DIW       D-Inside Wire [AT&T]
.DIZ      Description In Zip (file name extension)
DL        Download (also D/L)
DL/1      Data Manipulation Language 1 [IBM]
DLC       Data Link Control (protocol) [IBM] +
          Distributed Loop Carrier
DLCI      Data Link Connection Identifier
DLD       Display List Driver
DLE       Data Link Escape
DLL       Dynamic Link Library
DLM       Distributed Lock Manager + Dynamic Link Module
DLP       Digital Light Processing [TI]
DLR       DOS LAN Requester
DLS       Data Link Switching [IBM]
DLT       Digital Linear Tape
DM        Distributed Memory
DMA       Direct Memory Access/Addressing
DMAC      DMA Controller
DMACS     Distributed Manufacturing Automation & Control Software
DMD       Digital Micromirror Device [TI]
DME       Distributed Management Environment
DMF       Distribution Media Format [Microsoft]
DMI       Desktop Mangement Interface
DML       Data Manipulation Language
DMM       Digital Multimeter
DMMS      Dynamic Memory Management System
DMOS      Double-diffused Metal-Oxide Semiconductor
DMP       Dot Matrix Printer
DMPC      Distributed Memory Parallel Computer
DMQS      Display Mode Query and Set [IBM]
DMS       Data Management Software + Data/Document Management System
DMSD      Digital Multistandard Decoding
DMSS      Distributed Mass Storage System
DMT       Digital/Discrete Multi-Tone
DMTF      Desktop Management Task Force
DMY       Day Month Year
DN        Down
DNC       Direct Numerical Control
DNIC      Data Network Identification Code
DNIS      Dialed Number Identification Service
DNS       Domain Naming System
DO        Data Out + Distributed Objects
.DOC      Document + Documentation (file name extensions)
DOCSV     Data Over Circuit-Switched Voice
DOE       Distributed Objects Everywhere
DOIP      Dial Other Internet Providers [IBM]
DO-IT     Disabilities, Opportunities, Internetworking and
          Technology
DOM       Document Object Model
DOMF      Distributed Object Management Facility
DOS       Disk Operating System
DOSEM     DOS Emulation
DOV       Data Over Voice
DOW       Day Of Week
DP        Data Processing
DPA       Demand Protocol Architecture [3Com] +
          Document Printing Architecture
DPAM      Demand Priority Access Method
DPAREN    Data Parity Enable [IBM]
DPB       Drive Parameter Block
DPC       Direct Program Control
DPI       Distributed Protocol Interface + Dots Per Inch
DPL       Descriptor Privilege Level
DPM       Digital Panel Meter
DPMA      Data Processing Management Association
DPMI      DOS Protected Mode Interface [Microsoft]
DPMS      Display Power Management Support
DPO       Data Phase Optimization
DPS       Document Processing System
DPSK      Differential Phase Shift Keying
DPtoTP    Display Coordinates to Tablet Coordinates
          (converting)
DQDB      Distributed Queue Dual Bus
DQL       Data Query Language
DR        Data Received
D/R       Direct or Reverse
DRAM      Dynamic Random Access Memory
DRAW      Direct Read After Write
DR.BOND   Dial-up Router Bandwidth On Demand [NEC]
DRDA      Distributed Relational Database Architecture [IBM]
DR-DOS    Digital Research-Disk Operating System
DRDW      Direct Read During Write
DRI       Digital Research Incorporated
DRO       Data Request Output + Destructive Read-Out
DRS       Document Registration System
.DRS      Driver Resource (file name extension) [WordPerfect]
DRV       Drive
.DRV      Device Driver (file name extension) (Also see .DVR)
.DRW      Draw + Drawing (file name extensions)
DS        Data Segment + Data Send + Data Server + Double Sided
D/S       Dhrystone Per Second
DSA       Directory System Agent
DSAP      Destination Service Access Point
DSDD      Double Sided, Double Density (diskette)
DSE       Data Storage Equipment
DSEA      Display Station Emulation Adapter
DSECT     Dummy Control Section
DSHD      Double Sided, High Density (diskette)
DSIS      Distributed Support Information Standard
DSL       Digital Subscriber Line +
          Dynamic Simulation Language
DSLAM     Digital Subscriber Line Access Multiplexer
DSMA      Digital Sense Multiple Access
DSOM      Distributed System Object Model
DSP       Digital Signal Processing/Processor +
          Directory Synchronization Protocol [Lotus]
DSQD      Double Sided, Quad Density (diskette)
DSR       Data Set Ready + Device Status Register +
          Device Status Report
DSS       Decision Support System + Digital Signature Standard
DSSI      Digital Standard Systems Interconnect [DEC]
DSSS      Direct-Sequencing Spread Spectrum
DSTN      Double Supertwisted Nematic
DSU       Data Service Unit + Digital Service Unit
DSVD      Digital Simultaneous Voice and Data
DSW       Data Status Word + Device Status Word
DSX       Digital Signals Cross-Connect
D2T2      Dye Diffusion Thermal Transfer (printing)
DTA       Disk Transfer Area
.DTA      Data (file name extension)
DTC       Desktop Conferencing
DTD       Document Type Definition
DTE       Data Terminal Equipment + Dumb Terminal Emulator
DTF       Distributed Test Facility
DTL       Dialogue Tag Language [IBM] + Diode-Transistor Logic
DTMF      Data Tone Multiple Frequency + Dual Tone Multifrequency
DTP       Desktop Publishing + Distributed Transaction Process
DTR       Data Terminal Ready + Data Transfer Rate
DTV       Desktop Video
DTVC      Desktop Video Conferencing
DU        Disk Usage
DUA       Directory User Agent
DUAT      Direct User Access Terminal
DUN       Dial-Up Networking [Microsoft]
DUNCE     Dial Up Network Connection Enhancement
.DV       DESQview Script (file name extension)
DVC       Desktop Video Conferencing
DVD       Digital Video Disk
DVE       Digital Video Effect
DVI       Digital Video Interactive
.DVI      Device Independent (file name extension)
DVMRP     Distance Vector Multicast Routing Protocol [Internet]
.DVR      Device Driver (file name extension) (Also see .DRV)
DWG       Drawing
DWMT      Discrete Wavelet Multitone
D2X       Decimal To Hexadecimal [REXX]
.DXB      Drawing Interchange Binary (file name extension)
          [AutoCAD]
DXC       Data Exchange Control
DXF       Drawing Exchange Format
DXI       Data Exchange Interface

E...

EA        Effective Address + Extended Attribute [OS/2]
EAR       External Access Register
EARN      European Academic Research Network
EAROM     Electrically Alterable Read Only Memory
EARS      Electronic Access to Reference Services +
          Electronic Authoring and Routing System [DEC] +
          Explicit Archive and Retrieval System [Langley Research]
EATA      Enhanced AT Bus Attachment
EBC       EISA Bus Controller
EBCT      Electron Beam Computed Tomography
EBCDIC    Extended Binary Coded Decimal Interchange Code [IBM]
EBI       Equivalent Background Input +
          Extended Background Investigation
EBT       Electronic Benefits Transfer
EC        Electronic Commerce + Error Control
ECAL      Enjoy Computing And Learn
ECAT      Electronic Card Assembly and Test [IBM]
ECB       Electronic Codebook + Event Control Block
ECC       Elliptic Curve Crypto + Error Check Code +
          Error Checking and Correction + Error Correction Code
ECD       Enhanced Color Display + Enhanced Compact Disk
ECHO      European Commission Host Organization [Internet]
ECI       External Call Interface
ECL       Emitter Coupled Logic
ECM       Electronic Control Module
ECMA      European Computer Manufacturers Association
ECNE      Enterprise Certified NetWare Engineer [Novell]
ECP       Enhanced/Extended Capabilities Port [Microsoft]
ECTL      Electronic Communal Temporal Lobe
ECU       EISA Configuration Utility
ED        Erase Display
EDA       Electronic Design Automation +
          Embedded Document Architecture [Go Corporation]
EDC       Electronic Digital Computer +
          Enhanced Data Correction +
          Error Detection and Correction
EDDC      Extended Distance Data Cable
EDGAR     Electronic Data Gathering, Analysis and Retrieval
EDI       Electronic Data Interchange +
          Electronic Document Interchange [DEC]
EDIFACT   EDI for Administration Commerce and Transport
EDL       Edit Decision List
EDLC      Ethernet Data Link Control
EDLIN     Editor (Line Text)
EDMS      Electronic Document Management System
EDO       Extended Data Out
EDOS      Enhanced DOS for Windows
EDP       Electronic Data Processing
EDPM      Electronic Data Processing Machine
EDRAM     Extended Dynamic Random Access Memory
EDS       Electronic Data Systems (corporation)
EDSAC   * Electronic Delay Storage Automatic Computer
EDSI      Enhanced Small Device Interface
.EDU      Educational Institutions (Domain Name) [Internet]
EDVAC   * Electronic Discrete Variable Automatic Computer
          (First stored-program digital computer)
EE        Extended Edition [IBM]
EEC       Extended Error Correction
EEG       Electroencephalogram
EEL       Epsilon Extension Language
EEM       Extended Memory Management
EEMS      Enhanced Expanded Memory Specification
EEPROM    Electrically Erasable Programmable Read-Only Memory
EES       Escrow Encryption Standard
EFA       Extended File Attribute
EFF       Electronic Frontier Foundation
EFI       Electromechanical Frequency Interference +
          Electronics For Imaging
EFL       Emitter Follower Logic
E-FORM    Electronic Form
EFTS      Electronic Funds Transfer System
EGA       Enhanced Graphics Adapter
EGP       Exterior Gateway Protocol
EGREP     Extended Global Regular Expression Print [Unix]
EHLLAPI   Emulator High Level Language Application
          Programming Interface [IBM]
EIA       Electronic Industries Association
EIDE      Enhanced Integrated Drive Electronics
EIS       Executive Information System
EISA      Extended Industry Standard Architecture
EL        Electroluminescent (display) + Erase Line
ELAN      Emulated Local Area Network
ELC       Embedded Linking and Control
ELF       Executable and Linking Format +
          Extremely Low Frequency
ELS       Entry Level System
EM        Electronic Mail + Emphasized + End of Medium +
          Expanded Memory
EMA       Electronic Mail Association +
          Enterprise Management Architecture
EMACS     Editing Macros [Unix]
E-MAIL    Electronic Mail
EMB       Extended Memory Block [LIM/AST]
EMBARC    Electronic Mail Broadcast to a Roaming Computer
          [Motorola]
EMC       Electromagnetic Compatibility + Enhanced Memory Chip +
          E-Mail Connection + Extended Math Coprocessor
EMI       Electromagnetic Interference
.EML      Electronic Mail (file name extension)
EMM       Expanded Memory Manager
EMR       Electro-Magnetic Radiation +
          Enhanced Metafile Record
EMS       Electronic Mail System + Electronic Message Service +
          Expanded Memory Specification [LIM]
EMWAC     European Microsoft Windows NT Academic Centre
.ENC      Encoded (file name extension)
ENDEC     Encoder/Decoder
ENDS      Ends Segment
ENIAC   * Electronic Numerical Integrator Analyzer and
          Computer (First fully electronic digital computer)
ENQ       Enquiry
ENSS      Exterior Nodal Switching Subsystem [Internet]
EOA       End Of Address
EOB       End Of Block
EOC       End Of Conversion
EOF       End Of File + Enterprise Objects Framework [Next Computer]
EOI       End Of Interrupt + End Or Identify
EOJ       End Of Job
EOL       End Of Line + End Of List
EOM       End Of Message
EOR       Exclusive OR (Also XOR)
EOS       Earth Observing System [NASA] + End Of String
EOSDIS    Earth Observing System Data and Information System [NASA]
EOT       End Of Table + End Of Tape (marker) + End Of Text +
          End Of Transmission
EP        Electrophotographic Engine
EPIC      Explicitly Parallel Instruction Computing
EPL       Effective Privilege Level
EPLD      Electrically Programmable Logic Device
EPM       Enhanced Editor for Presentation Manager [IBM] +
          Enterprise Process Management [IBM]
EPP       Enhanced Parallel Port
EPROM     Electrically Programmable Read Only Memory +
          Erasable Programmable Read Only Memory
.EPS      Encapsulated PostScript (file name extension)
EPSF      Encapsulated PostScript Files
ERA       Extended Registry Attributes
ERAS      Electronic Routing and Approval System [Hughes Aircraft]
ERD       Emergency Repair Disk
ERIC      Educational Resources Information Center [Internet]
ERLL      Enhanced Run Length Limited
ERMA    * Electronic Recording Method, Accounting [General Electric]
EROM      Erasable Read Only Memory
EROS      Earth Resources Observation System [U.S. Geological Survey]
ERR       Error
ER/RC     Extended Result/Response Code
ERU       Emergency Recovery Utility [Microsoft]
ES        Extra Segment
ESA       Enterprise Systems Architecture [IBM] +
          European Space Agency
ESC       EISA System Component + Escape
ESCM      Extended Services Communications Manager [IBM]
ESCON     Enterprise System Connection (Architecture) [IBM]
ESC/P     Epson Standard Code for Printers
ESD       Electronic Software Distribution +
          Electrostatic Discharge
ESDI      Enhanced Small/System Device Interface
ESF       Extended Superframe
ESI       Enhanced Serial Interface (specification) [Hayes]
ESMR      Enhanced Specialized Mobile Radio
ESN       Electronic Security Number
ESP       Emulation Sensing Processor +
          Encapsulating Security Payload (header) +
          Enhanced Serial Port [Hayes] + Enhanced Service Provider +
          Estimated Selling Price
ESR       Event Service Routine
ESS       Electronic Switching System
ESU       Electro-Static Unit
ET        Enhancement Technology
ETACS     Extended Total Access Communication System [IBM]
ETANN     Electrically Trainable Analog Neural
          Network (chip) [Intel]
ETB       End of Transmission Block
ETC       Electronic Toll Collection +
          Enhanced Throughput Cellular (modem protocol) [AT&T]
ETOM      Electron-Trapping Optical Memory
ETPL      Endorsed Tempest Products List
ETS       Econometric Time Series
ETX       End Of Text
EU        Execution Unit
EUC       End User Computing + Extended Unix Code [IBM]
EUI       End-User Interface
EVE       Extensible VAX Editor
EVGA      Extended Video Graphics Array +
          Extended Video Graphics Adapter
EWAN      Emulator Without A Good Name [Internet]
EWS       Employee Written Software [IBM]
ExCA      Exchangeable Card Architecture [Intel]
.EXE      Executable (file name extension)
EXE2BIN   Program used to convert an (.EXE) file to binary
          format (.COM) file
EXM       Enterprise Messaging Exchange [Lotus]
EXP       Exponent
EXT       External
EXTRN     External Reference
E-ZINE    Electronic Magazine

F...

FAB       Computer-Chip Fabrication Plant
FAC       File Access Code
FAMOS     Floating Gate Avalanche MOS
FANS      Future Air Navigation System
FAP       File Access Protocol
FAPI      Family Application Program Interface
FAQ       Frequently Asked Question
FARNET    Federation of American Research Networks [Internet]
FASIC     Function and Algorithm-Specific Integrated Circuit
FAT       File Allocation Table
FAX       Facsimile
.FAX      Fax (file name extension)
FC/AL     Fiber Channel/Arbitrated Loop
FCB       File Control Block
FCC       Federal Communications Commission
FCC:      File Carbon Copy
FCCSET    Federal Coordinating Council for
          Science, Engineering and Technology
FC/EL     Fiber Channel/Enhanced Loop
FCI       Flux Changes per Inch
FCR       FIFO Control Register
FCS       Fiber Channel Standard + Frame Check Sequence
FD        Floppy Disk + Floppy Drive + Full Duplex
FDC       Floppy Disk Controller
FDDI      Fiber Digital Device Interface +
          Fiber Distributed Data Interface
FDISK     Fixed Disk
FDM       Frequency Division Multiplexing
FDMA      Frequency Division Multiple Access
FDX       Full Duplex
FECN      Forward Explicit Congestion Notification
FED       Field Emission/Emitter Display
FEFO      First-Ended, First-Out
FEP       Front End Processor
FEPI      Front End Programming Interface
FEPROM    Flash EPROM
FeRAM     Ferroelectric RAM
FESDK     Far East Software Development Kit [Microsoft]
FET       Field Effect Transistor
FF        Flip-Flop + Form Feed
FFDC      First Failure Data Capture [IBM]
FFS       Fast File System
FFST      First Failure Support Technology [IBM]
FFT       Fast Fourier Transform + Final Form Text [IBM]
FG        Floating Gate
FGREP     Fixed Global Regular Expression Print [Unix]
FHSS      Frequency-Hopping Spread Spectrum
FIF       Fractal Image Format
FIFO      First-In, First-Out
FILO      First-In, Last-Out
FIP       File Processor Buffering
FIPS      Federal Information Processing Standard
FIR       Fast Infrared + Finite Impulse Response
.FIRM     Business or Firm (Domain Name) [Internet]
FIRST     Forum of Incident Response and Security Teams
FIU       Fingerprint Identification Unit [Sony]
FIX       Federal Internet Exchange
FLA       Four Letter Acronym
FLC       Ferro-electric Liquid Crystal
FLD       Field
FLL       FoxPro Link Library [Microsoft Fox Pro]
FLOPS     Floating Point Operations Per Second
.FLR      Folder (file name extension)
FMS       Forms Management System
FMT       Format
FMV       Full Motion Video
FNT       Font
FOCUS     Forum of Control Data Users
FOD       Fax On Demand
FOG       First Osborne Group
FOIRL     Fiber Optic Inter Repeater Link [IEEE]
FOLDOC    Free On-Line Dictionary Of Computing
.FON      Font + Phone + Phone Directory (all file name
          extensions)
.FOR      Fortran source code (file name extension)
FORTH     (Programming Language)(See HLL)
FORTRAN   Formula Translator (Programming Language)(See HLL)
FOSE      Federal Office Systems Exposition
FOSI      Format Option Specification Instance
FOSSIL    Fido/Opus/Seadog Standard Interface Layer
FPC       Floating Point Calculation
FPCE      Floating-Point C Extension (specification)
FPGA      Field Programmable Gate-Array
FPLA      Field Programmable Logic-Array
FPM       Fast Page Mode
FPP       Fixed Path Protocol + Floating Point Processor
FPR       Floating-Point Register
FPS       Favorite Picture Selection + Frames Per Second
FPT       Forced Perfect Termination
FPU       Floating Point Unit
FQDN      Fully Qualified Domain Name [Internet]
FRAD      Frame Relay Access Device +
          Frame Relay Assembler/Disassembler
FRAG      Fragment + Fragmentation
FRAM      Ferroelectric Random-Access Memory
FRC       Funtional Redundancy Checking
FRED      Frame Editor + Front-End to Dish
FRPI      Flux Reversals Per Inch
.FRS      WordPerfect Graphics Driver (file name extension)
FS        File Separator
FSD       File System Driver [OS/2]
FSE       Full Screen Editor
FSF       Free Software Foundation [Internet]
FSK       Frequency Shift Keying
FSN       Full Service Network
FSP       File Service Protocol
FSR       Free System Resources
FST       Flat Square Tube (monitor)
F/T       Full Time
FTAM      File Transfer, Access and Management +
          File Transfer and Access Method
FTL       Flash Transition Layer [Intel]
FTM       Flat Tension Mask [Zenith]
FTP       File Transfer Protocol [Internet]
FTPD      File Transfer Protocol Daemon
FTTC      Fiber To The Curb
FTS       Federal Telecommunication System
FTX       Fault Tolerant Unix
FUI       File Update Information
FUNC      Function
FVT       Full Video Translation
FYI       For Your Information

G...

GA        General Availability
GAAP      Generally Accepted Accounting Principles
GAL       Generic Array Logic
GAPI      Gateway Application Programming Interface
GART      Graphics Address Relocation Table
GATT      Graphics Address Translation Table
Gb        Gigabit (1,024 megabits) +
          (One Billion Bits of Information)
GB        Gigabyte (1,024 megabytes) +
          (One Billion Characters of Information)
GCC       GNU C-Compiler [Unix]
GCR       Group Code Recording
GDA       Global Data Area
GDDM      Graphics Data Display Manager
GDG       Generation Data Group [IBM]
GDI       Graphical Device Interface
GDLC      Generic Data Link Control [IBM]
GDP       Graphic Draw Primitive
GDT       Geometric Dimensioning and Tolerancing +
          Global Descriptor Table +
          Graphics Development Toolkit
GECOS     General Electric Comprehensive Operating System
GEIS      General Electric Information Service (company)
GEM       Graphics Environment Manager (DRI Program)
GENIE     General Electric Network for
          Information Exchange
GEO       Geostationary Earth Orbit
GEOS      Graphic Environment Operating System [Geoworks]
GET       Get Execute Trigger
GGP       Gateway-Gateway Protocol [Internet]
GHZ       Gigahertz
.GID      Topics (file name extension) [Microsoft]
.GIF      Graphics Interchange Format (file name extension)
GIGO      Garbage In, Garbage Out
GII       Global Information Infrastructure
GILS      Government Information Locator Service
GIS       Geographic Information System +
          Global Information Solutions [AT&T]
GIX       Global Internet Exchange [Internet]
GKS       Graphical Kernel System
GL        Graphics Language
G/L       General Ledger
GLIS      Global Land Information System [US Geological Survey]
GLM       General Linear Models
GLOBE     Global Learning by Observations to Benefit
          the Environment [Internet]
.GLY      Glossary (file name extension) [Microsoft Word]
GML       Generalized Markup Language
GMP       Global Mobile Professional
GMR       Giant Magneto-Resistive
GMS       Global Management System +
          Global Messaging Service [Novell]
GMT       Greenwich Mean Time
GND       Ground (signal/system)
GNN       Global Network Navigator
GNU       Gnu's Not Unix (operating system)
GOSIP     Government Open Systems Interconnection Profile
.GOV      Governmental (Domain Name) [Internet]
GP        Gas Plasma + General Purpose
GPF       General Protection Fault
GPI       Graphics Programming Interface
GPIB      General Purpose Information/Interface Bus
GPR       General Purpose Register [IBM]
GPS       Global Positioning Satellite/System
GPSS    * General Purpose Systems Simulator (language)
GRADD     Graphics Adapter Device Driver [IBM]
GRE       Graphics Engine
GREP      Global Regular Expression Print
.GRF      Graph (file name extension)
.GRP      Group (file name extension)
GS        Group Separator
GSI       General Server Interface
GSM       Global Shared Memory +
          Global System for Mobile-Communications (network)
GSNW      Gateway Service for NetWare [Microsoft]
GSP       Generic Server Passer
GSTN      General Switched Telephone Network
GTE       General Telephone Electronics (corporation)
GTL       Gunning Transceiver Logic
GTO       Guide To Operations [IBM]
GTP     * Geometry Theorem Prover
GUI       Graphical User Interface
GUID      Globally Unique Identifier +
          Global Universal Identifier
GVT       Global Virtual Time
GW-BASIC  Gee Whiz BASIC
.gz       Compressed file (compressed filename extension -
          using GNU gzip compression/decompression program) [Unix]
GZIP      GNU Zip

H...

.H        Header (file name extension) [C]
HACMP     High Availability Cluster Multi-Processing [IBM]
HAL       Hard Array Logic + Hardware Abstraction Layer +
          House-Programmed Array Logic
HAL     * Heuristically Programmed Algorithmic (computer)
          [from 1968 movie "2001: A Space Odyssey"]
HAP       Host Access Protocol
HASP      Houston Automatic Spooling Priority (System)
HBA       Host Bus Adapter
HCL       Hardware Compatibility List
HCSS      High Capacity Storage System
HCU       Home Computer User
HD        Hard Disk + High Density
HDA       Head Disk Assembly
HDCD      High Definition Compatible Digital
HDF       Hierarchical Data Format [NCSA]
HDI       Head to Disk Interference
HDLC      High-Level Data Link Control
HDM       Hardware Device Module
HDR       Header
HDSC      High Density Signal Carrier [DEC]
HDSL      High-Data-Rate Digital Subscriber Line
HDSS      Holographic Data Storage System
HDT       Host Digital Terminal
HDTV      High Definition Television
HDVD      High Definition Volumetric Display
HDW       Hardware
HDX       Half Duplex
HERC      Hercules
HEX       Hexadecimal
HFC       Hybrid Fiber-Coaxial
HFS       Hierarchical File System [Macintosh]
HFT       High Function Terminal [IBM]
HGA       Hercules Graphics Adapter
HGCP      Hercules Graphics Card Plus
HH        Hour
HHLAPI    High-Level Language Application Programming Interface
HIF       Hyper-G Interchange Format
HIFD      High-Density Floppy Disk
HIL       Human Interface Link [HP]
HIMEM     High Memory
HIPPI     High Performance Parallel Interface
HLCO      High Low Close Open
HLL       High Level Language
HLLAPI    High Level Language Application Programming Interface
.HLP      Help (file name extension)
HLQ       High Level Qualifier
HLS       Hue, Luminance, Saturation (color model)
HLT       Halt
HMA       High Memory Area [Microsoft] +
          Hub Management Architecture
HMD       Head Mounted Display
HMM       Hidden Markov Model
HMMP      Hyper-Media Management Protocol
HMOS      High Density Metal Oxide Semiconductor +
          High Speed Metal Oxide Semiconductor
HMP       Host Monitoring Protocol
HOTT      Hot Off The Tree (electronic newsletter)
HP        Hewlett-Packard (Company)
HPC       Handheld Personal Computer
HPCC      High Performance Computing and Communications
HPDJ      Hewlett-Packard Desk Jet
HPFS      High-Performance File System
HPG       Hewlett-Packard Graphics
HPGL      Hewlett-Packard Graphics Language
HPIB      Hewlett-Packard Interface Bus
HPLJ      Hewlett-Packard Laser Jet
HPPA      Hewlett-Packard Precision Architecture
HPPI      High Performance Parallel Interface
HPR       High Performance Routing [IBM]
HPUX      Hewlett-Packard Unix
HPW       High Performance Workstation [Sun]
.HQX      BinHex (file name extension) [Macintosh]
HRIS      Human Resource Information System
HRG       High Resolution Graphics
HRMS      Human Resource Management System
HRTF      Head Related Transfer Function
HS        High Speed
HSB       Hue, Saturation, Brightness (color model)
HSC       Hierarchical Storage Controller + High Speed Channel
HSI       Hue, Saturation, Intensity
HSM       Hierarchical Storage Management
HSP       High Speed Printer
HSSI      High Speed Serial Interface
HST       High Speed Technology [U.S. Robotics]
.HST      History + Host (file name extensions)
HSV       Hue Saturation Value
HTML      HyperText Markup Language
HTTP      HyperText Transfer Protocol
HTTP-NG   HTTP Next Generation
HUD       Heads Up Display
HUT       Hopkins Ultraviolet Telescope
H/V       Horizontal/Vertical
HVP       Horizontal & Vertical Position
H/W       Hardware
HWCP      Hardware Code Page
HWD       Height-Width-Depth
.HYP      Hyphenation (file name extension)
HYTELNET  Hypertext-browser for Telnet Accessible Sites
Hz        Hertz

I...

IAB       Internet Architecture Board [Internet]
IAC       Inter-Application Communication [Macintosh]
IAG       Instruction Address Generation
IAK       Internet Access Kit [IBM]
IAL     * International Algebraic Language
          (ALGOL was first called IAL)
IANA      Internet Assigned Numbers Authority [Internet]
IAP       Internet Access Provider [Internet]
IAT       Import Address Table
IAUP      Internet User Account Provider [Internet]
IBC       Instrument Bus Computer
iBCS      Intel Binary Compatibility Specification
IBM       International Business Machines (Corporation)
IBM-GL    IBM Graphics Language
IC        Input Circuit + Integrated Circuit + Interrupt Controller
ICA       Intelligent Console Architecture +
          Intra-application Communications Area
ICAP      Internet Calendar Access Protocol [Lotus]
ICAS      Intel Communicating Applications Specifications
ICB       Internet Citizen's Band
ICCP      Institute for the Certification of Computing Professionals
ICE       In-Circuit Emulator [Intel] +
          Integrated Computing Environment [Langley Research]
ICES      Interference-Causing Equipment Standard
ICI       Image Component Information
ICL       Interface Clear
ICLID     Incoming-Call Line Identification
ICM       Image Color Matching [Kodak]
ICMP      Internet Control Message Protocol [Novell]
.ICO      Icon (file name extension)
iCOMP     Intel Comparative Microprocessor Performance [Intel]
ICP       Integrated Channel Processor
ICR       Intelligent Character Recognition
ICS       Intuitive Command Structure
ICSAPI    Internet Connection Services API
ICU       ISA Configuration Utility + Instruction-Cache Unit
ID        Identification + Identifier
IDA       Integrated Digital Access + Intelligent Disk Array +
          Intelligent Drive Array
IDAPI     Integrated Database Application Programming Interface
IDC       Integrated Database Connector +
          Integrated Desktop Connector +
          Internet Database Connector [Microsoft]
IDDE      Integrated Development & Debugging Environment [Symantec]
IDE       Imbedded Drive Electronics +
          Integrated Development Environment [Borland] +
          Integrated Drive Electronics +
          Intelligent Drive Electronics +
          Interactive Design and Engineering +
          Interface Design Enhancement
IDEA      International Data Encryption Algorithm
IDF       Intermediate Distribution Frame
IDIV      Integer Divide
IDL       Interactive Data Language +
          Interface Definition Language
IDMS      Integrated Data Base Management System
IDNX      Integrated Digital Network Exchange [IBM]
IDP       Integrated Data Processing
IDR       Intelligent Document Recognition
IDT       Interface Design Tool + Interrupt Descriptor Table
.IDX      Index (file name extension)
IE        Internet Explorer [Microsoft]
IEC       International Electrotechnical Commission
IEEE      Institute of Electrical and Electronics Engineers
IEF       Information Engineering Facility
IEMSI     Interactive Electronic Mail Standard
          Identification
IEN       Internet Engineering Notes
IETF      Internet Engineering Task Force [Internet]
IESG      Internet Engineering Steering Group [Inernet]
I/F       Interface
IFC       Internet Foundation Classes
IFD       Image File Directory
IFF       Interchangeable File Format [Amiga]
IFG       Incoming Fax Gateway
IFP       Instruction Fetch Pipeline
IFS       Installable File System
IFSM      Information Systems Management
IGA       Integrated Graphics Array
IGC       Integrated Graphics Controller
IGES      Initial Graphics Exchange Standard
IGMP      Internet Group Multicast Protocol [Internet]
IGP       Interior Gateway Protocol
IGRP      Interior Gateway Routing Protocol [Cisco]
IGS       Internet Go Server [Internet]
IHD       Integrated Help Desk [IBM]
IHV       Independent Hardware Vendor
IIF       Immediate Interface
III       Interstate Identification Index [NCIC]
IIOP      Internet Inter-Operability Protocol
IIR       Immediate Impulse Response
IIS       Internet Information Server [Microsoft]
IITF      Information Infrastructure Task Force
IKP       Internet Keyed Payments [IBM]
ILA       Image Light Amplifier
ILS       International Language Support
IMACS     Image Management and Communication System
IMAP      Internet Message Access Protocol [Internet]
IMAX      Maximum Image
IMDS      Image Data Stream (format) [IBM]
IME       Input Method Editor
IMG       Image
IML       Initial Microcode Load [IBM]
IMP       Information/Interface Message Processor
IMPA      Intelligent Multi-Port Adapter [DCA]
IMR       Internet Monthly Report [Internet]
IMS       Information Management System +
          Intermediate Maintenance Standards
IMSP      Internet Message Support Protocol
IMTC      International Multimedia Teleconferencing Consortium
IMTV      Interactive Multimedia Television
IMUL      Integer Multiply
IMUX      Inverse Multiplexer
IN        Input
INC       Increment
.IND      Index (file name extension)
.INF      Information (file name extension)
.INFO     Information Services (Domain Name0 [Internet]
.INI      Initialize (file name extension)
INIT      Initialization + Initialize
INM       Integrated Network Management
INND      Internet News Daemon
INS       Input String + Integrated Network Server
INT       Integer + Internal + Interrupt +
          International (organization Domain name) [Internet]
INTA      Interrupt Acknowledge
InterNIC  Internet Network Information Center [Internet]
INTO      Interrupt if Overflow occurs
I/O       Input/Output
IOC       Inter-Office Channel
IOCC      Input/Output Channel Converter +
          Input/Output Controller Chip
IOCS      Input/Output Control System
IOCTL     Input/Output Control
IODE      Integrated Development and Debugging Environment [Symantec]
IOP       Input/Output Processor
IOPL      Input/Output Privilege Level
IOSGA     Input/Output Support Gate Array
IP        Instruction Pointer + Internet Protocol
IPC       Instructions Per Clock + Interprocess Communication
IPCP      Internet Protocol Control Protocol
IPDS      IBM Personal Dictation System [IBM] +
          Intelligent Printer Data Stream [IBM]
IPFC      Information Presentation Facility Compiler [IBM]
IPI       Intelligent Peripheral Interface
IPL       Initial Program Load/Loader +
          Ion Projection Lithography
IPL     * Information Programming Language
IPM       Interpersonal Message
IPng      Internet Protocol, next generation
IPSE      Integrated Project Support Environment
IPTC      International Press Telecommunications Council
IPX       Internetwork Packet Exchange [Novell]
IQL       Interactive Query Language
IR        Infrared
IRC       Internet Relay Chat [Internet]
IRD       Integrated Receiver/Descrambler
IRDA      Infrared Data Association
IRDS      Information Resource Dictionary System
IRET      Interrupt Return
IRF       Intermediate Routing Function +
          Inheritance Rights Filter [Novell]
IRL       Interactive Reader Language + Inter-Repeater Link
IRLAP     Infrared Link Access Protocol
IRLED     Infrared Light Emitting Diode
IRM       Information Resource Management + Inherent Rights Mask
IRQ       Interrupt Request
IRTF      Internet Research Task Force [Internet]
IRX       Information Retrieval Experiment
IS        Information System + Interrupt Status
ISA       Industry Standard Architecture +
          Instruction-Set Architecture
ISAM      Indexed Sequential-Access Management/Method
ISAPI     Internet Servier API [Microsoft]
ISBN      International Standard Book Number
ISC       Instruction Set Computer + Inter-Systems Communication [IBM]
ISD       Image Section Descriptor +
          Instructional Systems Design
ISDN      Integrated Services Digital Network
ISH       Information Super Highway
ISI       Internally Specified Index
ISIS      Integrated Systems and Information Services
ISKM      Internet Starter Kit for the Macintosh
ISL       Interactive System Language
ISM       Internet Service Manager [Mircrosoft]
ISMF      Interactive Storage Management Facility
ISOC      Internet Society
ISO       International Organization for Standardization
ISP       Internet Service Provider [Internet] +
          Interrupt Stack Pointer + Interrupt Status Port
ISPF      Interactive System Programming Facility
ISR       Information Storage and Retrieval +
          Interrupt Service Routine +
          Interrupt Status Register
ISSN      International Standard Serial Number
ISV       Independent Software Vendor
IT        Information Technology
ITB       Information Technology Branch + Intermediate Text Block
ITC       International Typeface Corporation
ITE       Information Technology Equipment
ITF       Interactive Test Facility
ITN       Identification Tasking and Networking
ITR       Internet Talk Radio
ITU       International Telecommunication Union
ITUG      International Telecommunications User Group
ITU-TIES  ITU-Telecom Information Exchange Services
ITU-TSS   ITU-Telecommunication Standards Section
ITV       Interactive Television
ITX       Intermediate Text Block
IU        Integer Unit
IUAP      Internet User Account Provider [Internet]
IUS/ITB   Interchange Unit Separator/Intermediate Transmission
          Block
IVIS      Interactive Video Information System
IVL       Independent Vendor League + Intel Verification Lab
IVR       Interactive Voice Response
IVS       Interactive Videodisk System
IVT       Interrupt Vector Table
IV&V      Independent Verification & Validation
I-WAY     Information Highway
IXC       Interchange Carrier

J...

JA        Jump Address + Jump if Above
JAD       Joint Application Design
JAE       Jump if Above or Equal
JANET     Joint Academic Network
JAR       Java Archive File (format)
JBE       Jump if Below or Equal
JC        Jump if Carry set
JCL       Job Control Language
JDBC      Java Database Connectivity
JDK       Java Development Kit
JE        Jump if Equal
JEDEC     Joint Electronic Devices Engineering Council
JEIDA     Japanese Electronics Industry Development Association
JES       Job Entry System
JFC       Java Foundation Classes
JFET      Junction Field Effect Transistor
JFIF      JPEG File Interchange Format
JFS       Journaled File System [IBM]
JG        Jump if Greater
JGE       Jump if Greater or Equal
JIPS      JANET Internet Protocol Service
JIT       Just-In-Time (compiler)
JL        Jump if Less
JLE       Jump if Less than or Equal to
JMAPI     Java Management Application Program Interface
JMP       Jump
JNA       Jump if Not Above
JNAE      Jump if Not Above or Equal
JNB       Jump if Not Below
JNBE      Jump if Not Below or Equal
JNG       Jump if Not Greater
JNGE      Jump if Not Greater or Equal
JNI       Java Native Interface
.JNK      Junk (file name extension)
JNLE      Jump if Not Less or Equal
JNO       Jump if No Overflow
JNP       Jump if No Parity
JNS       Jump if No Sign
JOE       Java Objects Everywhere
JOHNNIAC* John Neumann Integrator and
          Automatic Computer [Rand Corp.]
JOSS    * Johnniac Open Shop System [Rand Corp.]
JPE       Jump if Parity Even
JPEG      Joint Photographic Experts Group
JPL       Jet Propulsion Laboratory
JPO       Jump if Parity Odd
JS        Jump if Sign
JZ        Jump if Zero
JNZ       Jump if Not Zero
JSS       Java-Script Style Sheet
JUGHEAD   Jonzy's Universal Gopher Hierarchy
          Excavation and Display [Internet]
JVM       Java Virtual Machine

K...

K-12      Kindergarten through 12th Grade [US Education System]
KAM       Keep Alive Memory
Kb        Kilobit
KB        Keyboard + Kilobyte (1,024 bytes)
KBD       Keyboard (also KEYB)
KBD$      Keyboard [OS/2]
Kbps      Kilobits Per Second
KBps      Kilobytes Per Second
KDT       Key Definition Table
KEFIR     Key Findings Reporter [GTE]
KEYBBE    Foreign language KEYBoard program - Belgium
KEYBBR    Foreign language KEYBoard program - Brazil
KEYBCF    Foreign language KEYBoard program - Canadian-French
KEYBCZ    Foreign language KEYBoard program - Czechoslovakia
(Czech)
KEYBDK    Foreign language KEYBoard program - Denmark
KEYBFR    Foreign language KEYBoard program - France
KEYBGR    Foreign language KEYBoard program - Germany
KEYBHU    Foreign language KEYBoard program - Hungary
KEYBIT    Foreign language KEYBoard program - Italy
KEYBLA    Foreign language KEYBoard program - Latin America
KEYBNL    Foreign language KEYBoard program - Netherlands
KEYBNO    Foreign language KEYBoard program - Norway
KEYBPL    Foreign language KEYBoard program - Poland
KEYBPO    Foreign language KEYBoard program - Portugal
KEYBSF    Foreign language KEYBoard program - Swiss-French
KEYBSG    Foreign language KEYBoard program - Swiss-German
KEYBSL    Foreign language KEYBoard program - Czechoslovakia
(Slovak)
KEYBSP    Foreign language KEYBoard program - Spain
KEYBSU    Foreign language KEYBoard program - Finland
KEYBSV    Foreign language KEYBoard program - Sweden
KEYBUK    Foreign language KEYBoard program - United Kingdom
KEYBUS    Foreign language KEYBoard program - United States
KEYBYU    Foreign language KEYBoard program - Yugoslavia
KHz       Kilohertz
KIF       Knowledge Interchange Format
KIS       Knowbot Information Service [Internet]
KPI       Kernel Programming Interface
KQML      Knowledge Query and Manipulation Language
KSH       Korn Shell (program) [Unix]
KSPH      Keystrokes Per Hour
KSR       Keyboard Send Receive
KRS       Knowledge Retrieval System

L...

L2F       Layer Two Forwarding [Cisco]
L2TP      Layer Two Tunneling Protocol
LADDR     Layered Device Driver Architecture [Microsoft]
LALL      Longest Allowed Lobe Length
LAN       Local Area Network
LANACS    Local Area Network Asynchronous Connection Server
LANDP     LAN Distributed Platform
LANE      Local Area Network Emulation
LAPB      Link Access Procedure Balanced (protocol)
LAPD      Link Access Procedure Direct (protocol)
LAPM      Link Access Procedure for Modems
LAR       Load Access Rights
LASER     Light Amplification by Stimulated Emission of Radiation
LASTport  Local Area Storage Transport (protocol) [DEC]
LAT       Local Access Terminal +
          Local Area Transport [DEC]
LATA      Local Access and Transport Area
LAVC      Local Area VAX Cluster
LAWN      Local Area Wireless Network
LB        Left Button (of 2 or 3 button Mouse)
LBA       Logical Block Addressing
LBL       Label
LBR       Librarian
.LBR      Library (file name extension)
LBT       Listen Before Talk
LBX       Local Bus Accelerator
LCA       Lotus Communications Architecture [Lotus]
LCC       Leadless Chip Carrier
LCD       Liquid Crystal Display + Lowest Common Denominator
LCF       Low Cost Fiber
LCK       Library Construction Kit [Microsoft FoxPro]
LCP       Link Control Protocol
LCR       Line Control Register
LCU       Last Cluster Used
LDA       Logical Device Address
LDAP      Lightweight Directory Access Protocol [IBM]
LDC       Lotus Development Corporation
LDDS      Long Distance Discount Services (company)
LDM       Long Distance Modem
LDT       Local Descriptor Table
LE        Less or Equal
LEA       Load Effective Address
LEAF      Law Enforcement Access Field
LEC       Local Area Network Emulation Client +
          Local Exchange Carrier
LED       Light Emitting Diode
LEL       Link, Embed and Launch-to-edit [Lotus]
LEM       Language Extension Module
LEN       Low Entry Networking
LES       Local Area Network Emulation Server
.LET      Letter (file name extension)
LEX       Lexicon
LF        Line Feed
LFI       Last File Indicator
LFN       Long File Name
LFT       Low Function Terminal [IBM]
LFU       Least Frequently Used
LGA       Leadless Grid Array
LGDT      Load Global Descriptor Table
LIAS      Library Information Access System
.LIB      Library (file name extension)
LIC       Line Interface Coupler [IBM]
LICS      Lotus International Character Set [LDC]
LIDT      Load Interrupt Descriptor Table
LIEP      Large Internet Exchange Packet [Novell]
LIF       Low Insertion Force
LIFO      Last In, First Out
LILO      Last In, Last Out
LIM       Lotus/Intel/Microsoft
LIMA      Lotus/Intel/Microsoft/AST
LIMDO     Light Intensity Modulation Direct Overwrite
LIMM      Light Intensity Modulation Method
LIMS      Library Information Management System
LINUX     (Operating system named after Linus Torvalds)
LIP       Large Internet Packet
LIPS      Lightweight Internet Person Schema +
          Logical Inferences Per Second
LISP      List Processing (Language)(See HLL)
LISTSERV  List Server [Internet]
LLC       Logical Link Control
LLDT      Load Local Descriptor Table
LLF       Low Level Format
LMB       Left Mouse Button
LMBCS     Lotus Multi-Byte Character Set [Lotus]
LMDS      Local Multipoint Distribution Service
LMI       Local Management Interface
LMS       Lotus Messaging Switch [Lotus]
LMSW      Load Machine Status Word
LMU       LAN Management Utilities [IBM] +
          LAN Manager for Unix
LN        Load Number + Logarithm (Natural)
LN:DI     Lotus Notes:Document Imaging
LNK       Link
LOAP      Lightweight Directory Access Protocol
LOC       Lines Of Code + Loop On-Line Control
LOCIS     Library of Congress Information System
LOD       Level Of Detail
LODSB     Load String Byte
LOG       Logarithm (Base 10)
LOGO      (Programming Language)(See HLL)
LON       Local Operating Network
LOOPE     Loop while Equal
LOOPNE    Loop while Not Equal
LOOPNZ    Loop while Not Zero
LOOPZ     Loop while Zero
LORE      Line Oriented Editor
LPAR      Logic Programming and Automated Reasoning
LPC       Local Procedure Call
LPD       Line Printer Daemon (protocol) [Berkley]
LPI       Lines Per Inch
LPL       Lotus Programming Language [Lotus 1-2-3] [LDC]
LPM       Lines Per Minute
LPN       Logical Page Number
LPR       Line Printer Remote
LPS       Low-Power Schottky
LPT       Line Printer
LPT1      First Parallel Printer Port
LPT2      Second Parallel Printer Port
LPT3      Third Parallel Printer Port
LQ        Letter Quality
LQM       Link Quality Monitoring (protocol)
LR        Link Register
LRC       Local Register Cache +
          Longitudinal Redundancy Check
LRL       Least Recently Loaded
LRM       Language Reference Manual + Least Recently-Used Master
.LRS      Language Resource (file name extension) [WordPerfect]
LRU       Least Recently Used
LSA       LAN and SCSI Adapter [IBM] + Line Sharing Adapter +
          Local Security Authority [Microsoft]
LSAPI     License Services Application Program Interface
LSB       Least Significant Bit
LSC       Least Significant Character
LSD       Least Significant Digit
LSI       Large Scale Integration
LSL       Link Support Layer + Load Segment Limit
LST       List
.LST      List (file name extension)
LTR       Left-To-Right + Letter + Load Task Register
LU        Logical Unit (Also LUN)
LUA       Logical Unit Application (interface)
LUI       Local User Input
LUIS      Library User Information Service
LUN       Logical Unit Number
LUT       Lookup Table
LV        Logical Volume [IBM]
LVM       Logical Volume Management [IBM]
LW        Lazy Write
.LYR      Lyrics (music file name extension)
LZW       Lempel-Ziv-Welch (algorithm)

M...

mA        Milliampere
Mac       Macintosh (Apple Macintosh Computer)
MAC       Media/Medium Access Control
.MAC      MacPaint (file name extension) +
          Macro (file name extension)
MACH      Multilayer Actuator Head [Epson]
MADE      Manufacturing and Automated Design Engineering
MADYMO    Mathematical Dynamic Modeling [TNO]
MAE       Metropolitan Area Ethernet
MAh       Milliampere-Hour
MAI       Multiple Applications Interface
.MAI      Mail (file name extension)
MAN       Manual [Unix] + Metropolitan Area Network
MANIAC  * Mathematical Analyzer Numerical
          Integrator and Computer
MANPAGE   Manual Page [Unix]
MAP       Maintenance Analysis Procedures +
          Manufacturing Automation Protocol +
          Memory Allocation Map
.MAP      Linker Map (file name extension)
MAPI      Mail/Messaging Applications Programming
          Interface [Microsoft]
MAPICS    Manufacturing, Accounting and Production
          Information Control System [IBM]
MARVEL    Machine-Assisted Realization of the Virtual
          Electronic Library [Library of Congress]
MASM      Macro Assembler [Microsoft]
MASS      Maximum Availability and Support
          Subsystem [Parallan]
MAT       Maintenance Access Terminal
MAU       Media Access/Adapter Unit + Multistation Access Unit
MAVDM     Multiple Application VDM
MAX       Maximum
MB        Megabyte (1,024 kilobytes) +
          Middle Button (of 3 button Mouse)
MBASIC    Microsoft BASIC [Microsoft]
MBCS      Multi-Byte Character Set [IBM]
MBONE     Multicast Backbone [Internet]
MBps      Megabytes Per Second
Mbps      Megabits Per Second
MBR       Master Boot Record
MBX       Mailbox
MCA       Micro Channel Adapter/Architecture [IBM]
MCAD      Mechanical Computer Aided Design
MCB       Memory Control Block
MCGA      Multicolor Graphics Array
MCI       MCI Communications Corp. (name from initials of
          original company - Microwave Communications, Inc.) +
          Media Control Interface [Microsoft]
MCL       Microsoft Compatibility Labs [Microsoft]
MCM       Multi-Chip Module
MCNE      Master Certified Novell Engineer [Novell]
MC-PGA    Metallized Ceramic - Pin Grid Array
MCPS      Microsoft Certified Product Specialist [Microsoft]
MC-QFP    Metallized Ceramic - Quad Flat Pack
MCR       Modem Control Register
MCU       Microcontroller Unit + Multi-Chip Unit [DEC] +
          Multipoint Control Unit
MD        Make Directory + Mini Disk [Sony] + Monochrome Display
MDA       Monochrome Display Adapter +
          Multidimensional Analysis
MDDBMS    Multidimensional Data Base Management System
.MDF      Menu Definition File (file name extension)
MDI       Memory Display Interface +
          Multiple Document Interface
MDIC      Manchester Decoder and Interface Chip [AT&T]
MDK       Multimedia Developers Kit [Microsoft]
MDLP      Modile Data Link Protocol
MDR       Minimum Design Requirement
MDY       Month Day Year
.ME       Opening Information (file name extension) (As in READ.ME)
MEB       Memory Expansion Board
MEG       Megabyte
MEM       Memory
.MEN      Menu (file name extension)
MERCI     Multimedia European Research Conferencing Integration
MES       Manufacturing Execution System
MESI      Modified, Exclusive, Shared and Invalid (protocol)
MET       Memory Enhancement Technology [Hewlitt-Packard]
.MET      Metafile (file name extension)
MFC       Microsoft Foundation Class [Microsoft]
MFFS      Microsoft Flash File System [Microsoft]
MFLOPS    Million Floating Point Operations Per Second
MFM       Modified Frequency Modulation
MFP       Multi-Function Peripheral/Product
MFPI      Multifunction Peripheral Interface
MFS       Macintosh File System [Macintosh] +
          Magnetic Tape Field Search + Memory File System
          Modified Filing System [Revelation Technologies]
MFT       Master File Table +
          Multiprogramming with a Fixed number of Tasks
MGA       Monochrome Graphics Adapter
MGE       Modular GIS Environment
MGET      Multiple Get [Unix]
MGR       Manager
MHS       Message Handling Service + Message Handling System
MHz       Megahertz
MI        Management Interface
MIB       Management Information Base
MICRO     One-millionth
MICS      Macro Interpretive Commands
MIDI      Musical Instrument Digital Interface
MIF       Management Information Format
.MIF      Management Information Files (file name extension)
MIG       Metal In Gap
MII       Microsoft/IBM/Intel
MIL       Machine Interface Layer [Go Corporation] +
.MIL      Military (Domain name) [Internet]
MIM       Metal-Insulator-Metal (screen)
MIMD      Multiple Instruction Multiple Data Stream (processor)
MIME      Multipurpose Internet Mail Extension [Internet]
MI/MIC    Mode Indicate/Mode Indicate Common
MIN       Minimum + Mobile Identification Number
MINUET    Minnesota Internet Users Essential Tools [Internet]
MIPS      Million Instructions Per Second
MIS       Management Information System +
          Multimedia Information Sources [Internet]
MISC      Miscellaneous
MIX       Member Information Exchange
MKDIR     Make Directory
ML        Machine Language + Meta Language
MLAPI     Multilingual Application Programming Interface
MLC       Multilayer Ceramic +
          Multilevel Cell (program) [Internet]
MLE       Multi-Line Editor
MLID      Multi-Link Interface Driver
MLM       Mailing List Manager [Internet]
MM        Minutes + Month
MMA       Microcomputer Managers Association
MMC       Matched Memory Cycle + Microcomputer Marketing Council +
          Microsoft Management Console [Microsoft]
MMCD      MultiMedia Compact Disk
MMCX      Multimedia Communication Exchange [Lucent Technologies]
MMI       Man-Machine Interface
MMIS      Materials Manager Information System
MMPM      Multi Media Presentation Manager
MMU       Memory Management Unit
MMVF      Multimedia Video File [NEC]
MMX       Matrix Manipulation Extensions [Intel] +
          Multimedia Extensions
MNOS      Metal Nitride Oxide Semiconductor
MNP       Microcom Networking Protocol [Microcom]
.MNU      Menu (fine name extension)
MO        Magneto-Optical (disk drive)
MOB       Memory-Order Buffer
MOBO      Mother Board
MOD       Module + Modulus
MODEM     Modulator Demodulator
MOHLL     Machine Oriented High Level Language
MOLAP     Multidimensional On-Line Analytical Processing
MOM       Microsoft Office Manager [Microsoft]
MONO      Monaural
MOO       MUD, Object Oriented [Internet]
MOP       Maintenance Operations Protocol
MOS       Magneto-Optic Storage + Mean Opinion Score +
          Metal Oxide Semiconductor
MOSFET    Metal Oxide Semiconductor Field Effect Transistor
MOTD      Message Of The Day
MOV       Metal Ocide Varistor + Move
MOVS      Move String
MP        Massively Parallel (processing) + Multiple Processors
MPC       Multimedia Personal Computer + Multipath Channel
MPCS      Mission Planning and Control Station (Software)
MPE       Multiple Programming Executive [HP]
MPEG      Motion Picture Experts Group
MPI       Message Passing Interface + Multiprecision Integer
MPM       Message Passing Library [IBM]
MPMD      Multiple Processor/Multiple Data
MPOA      Multi-Protocol over Asynchronous-Transfer-Mode
MPP       Massively Parallel Processing +
          Message Posting Protocol + Message Processing Program
MPQP      Multi-Protocol Quad Port [IBM]
MPR       Multipart Repeater + Multi Protocol Router [Novell]
MPS       Multiprocessor Specification
MPTN      Multi-Protocol Transport Network
MPTS      Multi-Protocol Transport Services
MPU       Microprocessor Unit
MQI       Message Queue Interface
MR        Magnetoresistive + Modem Ready
MRCF      Microsoft Realtime Compression Format
MRCI      Microsoft Realtime Compression Interface
MRI       Magnetic Resonance Imaging
MRM       Most Recently-Used Master
MRO       Multi-Region Operation
MRP       Materials Requirement Planning
MRPL      Main Ring Path Length
MRS       Media Recognition System
MRT       Mean Repair Time
MRU       Maximum Receive Unit
MS        Memory System + Message Store + Microsecond +
          Microsoft Corporation + Millisecond
MSACM     Microsoft Audio Compression Manager [Microsoft]
MSAU      Multi-Station Access Unit
MSAV      Microsoft Anti Virus [Microsoft]
MSB       Most Significant Bit
MSBF      Mean Swaps Between Failures
MSCDEX    Microsoft Compact Disc Extensions [Microsoft]
MSD       Mass Storage Device + Most Significant Digit +
          Microsoft System Diagnostics [Microsoft]
MSDN      Microsoft Developer Network [Microsoft]
MS-DOS    Microsoft - Disk Operating System [Microsoft]
MSDR      Multiplexed Streaming Data Request
MSDS      Microsoft Developer Support [Microsoft]
MSFR      Minimum Security Function Requirements [IBM]
MSG       Message
.MSG      Program Message (file name extension)
MSI       Medium Scale Integration
MSIE      Microsoft Internet Explorer [Microsoft]
MSL       Map Specification Library + Mirrored Server Link
MSN       Microsoft Network [Microsoft]
MSO       Multiple-Systems Operator
.MSP      Microsoft Paint (file name extension) [Microsoft]
MSRP      Manufacturer Suggested Retail Price
MSS       Mass Storage System +
          Multiprotocol Switched Services [IBM]
MSW       Machine Status Word
MTA       Message Transfer Agent + Multiple Terminal Access
MTBB      Mean Time Between Breakdowns
MTBF      Mean Time Between Failures
MTBJ      Mean Time Between Jams
MTF       Microsoft Tape Format [Microsoft] +
          Modulation Transfer Function
MTS       Message Transfer Service/System +
          Microsoft Transaction Server [Microsoft] +
          Multichannel Television Sound
MTT       Multi-Transaction Timer
MTTD      Mean Time To Diagnose
MTTF      Mean Time To Failure
MTTR      Mean Time To Repair
MTU       Maximum Transmission Unit
MUA       Mail User Agent
MUD       Multi-User Dialogue/Dimension/Domain/Dungeon [Internet]
MUL       Multiply
MUMPS     Massachusetts General Hospital Utility
          Multi-Programming System (Programming Language)
MUSE      Multi-User Shared Environment
MUT       Monitor Under Test
MUX       Multiplexer
MV        Millivolt
MVB       Multimedia Viewer Book
MVC       Multimedia Viewer Compiler
MVDM      Multiple Virtual DOS Machines
MVGA      Monochrome Video Graphics Array
MVIP      Multi-Vendor Integration Protocol
MVP       Multimedia Video Processor
MVS       Multiple Virtual Storage
MVT       Multiprogramming with a Variable number of Tasks
MX        Mail Exchanger [Internet]
MXS       Microsoft Exchange Server [Microsoft]
MZR       Multiple Zone Recording

N...

NAC       Network Adapter Card
NACD      National Association of Computer Dealers
NACS      National Advisory Committee on Semiconductors
NAE       Not Above or Equal
NAK       Negative Acknowledgment
NAM       Number Assignment Module
NAMPS     Narrow-Band Analog Mobile Phone Service [Motorola]
NANO      One thousand-millionth
NAP       Network Access Point
NAPLPS    North American Presentation Level Protocol
          Syntax (graphics)
NAS       Network Access Server + Network Application Support [DEC]
NASA      National Aeronautics and Space Administration
NASDAQ    National Association of Securities Dealers
          Automatic Quotation
NASI      NetWare Asynchronous Services Interface [Novell]
NASIRC    NASA Automated Systems Internet Response Capability
NASKER    NASA Ames Kernel (benchmark)
NAU       Network Addressable Unit
NAWS      Negotiate About Window Size
NBE       Not Below or Equal
NBI       Nothing But Initials
NBS       National Bureau of Standards + Numeric Backspace
NC        Network Computer + No Carry + Numerical Control
NCA       Network Communications Adapter +
          Network Computing Architecture [Oracle]
NCC       Network Control Center
NCD       Network Computing Device
.NCF      Netware Command File [Novell]
NCGA      National Computer Graphics Association
NCIC      National Crime Information Center
NCMT    * Numerical Control for Machine Tools
NCOS      Network Computer Operating System
NCP       NetWare Core Protocol + Not Copy Protected +
          Network Control Processor/Program/Protocol
NCR       National Cash Register (Company)
NCSA      National Center for Supercomputing Applications
NCSC      National Computer Security Center
NCSI      Network Communications Services
          Interface [Network Products Corp.]
NDB       Non-Directional Beacon
NDDK      Network Device Development Kid [Microsoft]
NDEF      Not to be Defined
NDIS      Network Device/Driver Interface Specification
NDN       Non-Delivery Notice
NDP       Numeric Data Processor
NDR       Network Data Representation
NDRO      Non-Destructive Read Out
NDS       NetWare Directory Service [Novell]
.NDX      Index (file name extension)
NEC       Nippon Electric Company
NED       NASA Extragalactic Database [NASA]
NEG       Negative + Negate
NEP       Network Entry Point
NES       National Education Supercomputer
NEST      Novell Embedded Systems Technology [Novell]
.NET      Networks (Domain Name) [Internet]
NetBIOS   Network Basic Input/Output System [IBM]
NetBEUI   NetBIOS Extended User Interface [IBM]
NETMON    Network Monitor
.NEW      New Information (file name extension)
NEWS      NetWare Early Warning System [Frye Computer] +
          Network Extensible Window System
NEWS.     Current events [USENET Newsgroup Category]
NEXT      Near-End Crosstalk
NFF       No Fault Found
NFS       Network File System [Sun]
NG        No Good
NGE       Not Greater or Equal
NHC       National Hurricane Center
NHR       National Handwriting Recognition
NHRP      Next Hop Resolution Protocol
N/I       Non-Interlaced
NIA       Next Instruction Address
NIC       Network Information Center [Internet] +
          Network Interface Card +
          Numeric Intensive Computing
NICAD     Nickel-Cadmium
NICOLAS   Network Information Center OnLine Aid System [NASA]
NID       New Interactive Display [NEC] + Next ID
NII       National Information Infrastructure
NIM       Network Installation Management [IBM]
NIMH      Nickel-Metal Hydride
NIO       Native Input/Output
NIPS      Network I/Os Per Second
NIR       Network Information Retrieval
NIS       Network Information Service [Unix]
N-ISDN    Narrowband ISDN + National ISDN
NISO      National Information Standards Organization
NISP      Networked Information Services Project
NIST      National Institute for Standards and Technology
NITC      National Information Technology Center
NIU       Network Interface Unit
NJE       Network Job Entry (protocol) [IBM]
NL        New Line
NLE       Not Less or Equal
NLM       NetWare Loadable Module [Netware]
NLP       Natural-Language Processing
NLQ       Near Letter Quality
NLSFUNC   National Language Support Function
NLV       National Language Version [IBM]
NMI       Non-Maskable Interrupt
NMM       NetWare Management Map [NetWare]
NMOS      Negative Channel Metal-Oxide Semiconductor
NMP       Network Management Protocol [AT&T]
NMS       Network Management System [Novell]
NN        Network Node + No News [Internet]
NNI       Network-Network Interface
NNTP      Network News Transfer Protocol [Internet]
NOC       Network Operations Center
.NOM      Individual with Personal Site (Domain Name) [Internet]
NOP       No Operation
NOPAC     Network OPAC
NOR       Not Or
NOS       Network Operating System
NPA       Network Printer Alliance
NPI       Network Printer Interface
NPL       Nonprocedural Language
NPS       Novell Productivity Specialist [Novell]
NPTN      National Public Telecomputing Network
NPU       Natural Processing Unit
NPX       Numeric Processor Extension
NQS       Network Queing System [Cray]
NRC       National Research Council (Canada)
NREN      National Research and Education Network
NRZ       Not Return to Zero
NRZI      Non Return to Zero Inverted
NS        Nanosecond + National Semiconductor (as in Ns16550 UART) +
          Network Supervisor + Non Stop
NSAP      Network Service Access Point
NSAPI     Netscape Server API [Netscape]
NSA POLY  National Security Agency Polygraph
NSERC     National Sciences and Engineering Research Council (Canada)
NSF       National Science Foundation
NSFNET    National Science Foundation Network
NSI       NASA Science Internet
NSLOOKUP  Name Server Lookup [Unix]
NSM       Netscape Server Manager [Netscape]
NSP       Native Signal Processing [Intel] + Network Service Provider
NSSC      NASA Standard Spacecraft Computer
NSTC      National Science and Technology Council
NSTL      National Software Testing Labs
NT        New Technology [Microsoft]
NT-1      Network Terminator Type 1
NTAS      NT Advamced Server [Microsoft]
NTF       No Trouble Found
NTFS      New Technology File System [Microsoft]
NTIA      National Telecommunications and
          Information Administration
NTIS      National Technical Information Service
NTRAS     NT Remote Access Services [Microsoft]
NTSA      NetWare Telephony Services Architecture [Novell]
NTSC      National Television Standards Committee
NUI       Network User Identification +
          Network User Interface +
          Notebook User Interface [Go Corporation]
NUL       Null + (dummy device) + (no device)
NUMA      Non-Uniform Memory Access
NV        No Overflow
NVM       Non-Volatile Memory
NVOD      Near-Video On Demand
NVP       Nominal Velocity of Propagation
NVRAM     Non-Volatile Random Access Memory
NVT       Network Virtual Terminal +
          Novell Virtual Terminal [Novell]
NWS       NetWare Web Server [Netware]
NYM       Anonymous

O...

OAB       One-to-All Broadcast
OAD       Open Architecture Driver [Bernoulli]
OAG       Official Airline Guide + Online Air Guide
OAI       Open Applications Interface
OAS       One-to-All Scatter
OBD       On Board Diagnostics
OBEX      Object Exchange [Borland]
OBJ       Object
OC        Optical Carrier
OCE       Open Collaborative Environment [Apple]
OCF       Objects Components Framework [Borland]
OCL       Operation Control Language + Operator Control Language
OCR       Optical Character Recognition
OCS       On-Card Sequencer
OCX       OLE Custom Control
ODA       Office Document Architecture
ODAPI     Open Database Application Programming
          Interface [Borland]
ODBC      Object-Oriented Database Connectivity +
          Open Data Base Connectivity [Microsoft]
ODBMS     Object-Oriented Database Management System  (also
          see OODMS)
ODI       Open Datalink Interface [Novell] +
          Open Device Interconnect [NetWare]
ODM       Object Data Manager [IBM] +
          Optimized Distribution Model [Compaq]
ODMA      Open Document Management API
ODP       Open Distributed Processing
ODS       Open Data Services [Microsoft]
ODSI      Open Directory Service Interface [Microsoft]
ODT       Open Desktop
OEM       Original Equipment Manufacturer
OEP       Operand Execution Pipeline
OF        Overflow Flag
OFB       Output Feedback (mode)
OFMT      Output Format for Numbers
OFS       Object File System [Microsoft] + Output Field Separator
OH        Off Hook
OIDL      Object Interface Definition Language
OIS       Office Information Systems
OLAP      On-Line Analytical Processing
.OLD      Old version (file name extension)
OLE       Object Linking and Embedding [Microsoft]
OLGA      On-Line Guitar Archive
OLI       Optical Line Interface [AT&T]
OLMC      Output Logic Macrocell
OLSP      On-Line Service Provider
OLTP      On-Line Transaction Processing
OM        Object Manager
OMA       Object Management Architecture [Microsoft]
OME       Open Messaging Environment (protocol)
OMF       Object Module Format [Microsoft] +
          Open Media Framework + Open Message Format
OMG       Object Management Group
OMI       Open Messaging Interface [Lotus]
OMNS      Open Network Management System
OMR       Optical Mark Recognition
ONC       Open Network Computing [Sun]
ONDS      Open Network Distribution Services [IBM]
ONE       Open Network Environment [Netscape]
ONU       Optical Network Unit
OODB      Object-Oriented Database
OODMS     Object-Oriented Database Management System (also
          see ODBMS)
OOL       Object-Oriented Language
OOOS      Object-Oriented Operating System
OOPL      Object-Oriented Programming Language
OOPS      Object Oriented Programming and Systems
OOS       Object-Oriented Systems +
          Off-line Operating Simulator
OOT       Object-Oriented Technology
OOUI      Object Oriented User Interface
OP        Operation + Optical + Output
OPAC      Online Public Access Catalog [Internet]
OPC       Organic/Optical Photoconductor
OPCODE    Operational Code
OPD       Operand
OPI       Open Prepress Interface
OPM       Operations Per Minute
OPS       Open Profiling Standard + Operations
OPT       Open Protocol Technology
.OPT      Options (file name extension)
OPUS      Octal Program Updating System
ORACLE    On-Line Inquiry and Report Generator (UNIX DB program)
ORB       Object Request Broker [Microsoft]
ORDVAC  * Ordnance Variable Automatic Computer
.ORG      Non-Profit Organizations (Domain name) [Internet]
ORI       Online Retrieval Interface
.ORI      Original (file name extension)
ORS       Output Record Separator
OS        Operating System
OS/2      Operating System/2 [IBM]
OSA       Open Scripting/System Architecture
OS/E      Operating System/Environment
OSF       Open Software Foundation
OSI       Open Systems Interconnection
OSM       Off-Screen Model
OSP       On-Screen Programming + Optical Storage Processor
OSPF      Open Shortest Path First
OSQL      Object Structured Query Language
OSR2      OEM Service Release 2 [Microsoft]
OT        Object Technology
OTA       Operation-Triggered Architecture
OTDR      Optical Time Domain Reflectometer
OTF       Open Token Foundation
OTP       One-Time Programmable
OURS      Open Users Recommended Solutions
.OUT      Outlines (file name extension)
OUTS      Output String
OV        Overflow
OVAL      Object-Based Virtual Application Language [Psion]
.OVL      Program Overlay (file name extension)
.OVR      Program Overlay (file name extension)
OWL       Object/Open Windows Library [Borland]

P...

PAB       Personal Address Book
PABX      Private Automatic Branch Exchange
PACE      Priority Access Control Enabled [3Com]
PACS      Picture Archiving and Communication System
PACS-L    Public Access Computer Systems List [Internet]
PAD       Packet Assembler/Disassembler
PADS      Pen Application Development System [Slate Corporation]
PAIH      Public-Access Internet Host [Internet]
PAIS      Public-Access Internet Site [Internet]
.PAK      Packed (compressed file name extension) [NoGate
Consulting]
PAL       Paradox Applications Language [Borland] +
          Phase Alternating Line + Programmed Array Logic +
          Programming Assembly Language
.PAL      Palette (file name extension)
PALC      Plasma-Addressed Liquid Crystal (display)
PALS      Principles of the Alphabet Literacy System
PAM       Pulse Amplitude Modulation
PAP       Packet-level Procedure +
          Password Authentication Protocol +
          Printer Access Protocol
PAR       Personal Animation Recorder + Parallel
PARA      Paragraph
PARC      Palo Alto Research Center [XEROX]
.PAS      PASCAL source code (file name extension)
PASCAL    (Programming Language named for Blaise Pascal)
.PAT      Patch + Pattern (file name extensions)
PATN      Promotional Port Access Telephone Number
PAX       Portable Archive Exchange [Unix]
PBE       Prompt By Example
PBGA      Plastic Ball Grid Array
PBX       Private Branch Exchange
PC        Personal Computer + Printed Circuit + Program Counter
PCACIAS   Personal Computer Automated Calibration Interval
          Analysis System
PCB       Printed Circuit Board + Program Control Block
PCBC      Plain Cipher Block Chaining
PCD       Photo Compact Disk
PC-DOS    Personal Computer - Disk Operating System [IBM]
PCEB      PCI to EISA Bridge [Intel]
PCI       Peripheral Component Interconnect/Interface
PCIC      PC-Card Interrupt Controller
PC-I/O    Program Controlled I/O
PCL       Printer Command Language [HP] + Process Control Language
PCM       Personal Computer Manufacturer +
          Printer Cartridge Metric [HP] +
          Pulse Code Modulation
PCMC      PCI, Cache, Memory Controller [Intel]
PCMCIA    Personal Computer Memory Card International Association
PCMIM     Personal Computer Media Interface Module
PCN       Personal Computer Network
PCNFS     Personal Computer Network File System
PCO       Point of Control and Observation
PCS       Patchable Control Store +
          Personal Communication Services/System +
          Personal Conferencing Specification +
          Planning Control Sheet + Print Contrast Signal +
          Process Control Systems + Program Counter Store +
          Programmable Drive Table + Project Control System
PCT       Private Communications Technology
.PCT      Picture (file name extension)
.PCX      Picture Image (file name extension)
PD        Phase-Change Dual + Public Domain
PDA       Personal Digital Assistant
PDC       Primary Domain Controller
PDD       Physical Device Driver + Portable Digital Document
PDF       Package Definition File + Portable Document Format +
          Portable Document File + Processor Defined Function +
          Program Development Facility
.PDF      Printer Description (file name extension)[Borland,Lotus]
PDIAL     Public Dialup Internet Access List [Internet]
PDL       Page Description Language + Program Description Language
          + Program Design Language
PDM       Product Data Management
PDN       Public Data Network
PDO       Portable Distributed Objects [Next]
PDP       Plasma Display Panel + Programmable Data Processor +
          (DEC Computer System Designation, i.e. PDP-8, PDP-11)
PDS       Packet Driver Specification + Partitioned Data Set +
          Planetary Data System + Portable Document Software +
          Processor Direct Slot [Macintosh]
PDSS      Post Development and Software Support
PDT       Performance Diagnostic Tool [IBM] +
          Programmable Drive Table
PDU       Plug Distribution Unit
.PDX      Paradox files (file name extension) [Borland] +
          Printer Description Extension (file name extension)
PE        Parity Even + Processing Element + Protect Enable
PEA       Pocket Ethernet Adapter
PEL       Picture Element [IBM]
PEM       Privacy-Enhanced Mail [Internet]
PEN SDK   Pen Computing Software Development Kit
PEP       Packet Exchange Protocol +
          Packetized Ensemble Protocol [Telebit]
PERL      Practical Extraction and Report Language [Unix]
PERT      Program Evaluation and Review Technique
PES       Positioning Error Signal + Processor Enhancement Socket
          Processor Upgrade Socket
PET       Print Enhancement Technology [Compaq]
.PFB      Printer Font Binary (file name extension)
PFE       Programmer's File Editor
.PFM      Printer Font Metrics (file name extension) [Windows]
PFR       Power-Fail Restart
PGA       Pin Grid Array + Professional Graphics Adapter [IBM]
PGC       Program Group Control [Microsoft]
PGDN      Page Down
.PGL      Graphics (file name extension) [Hewlett-Packard]
PGM       Program
PGP       Pretty Good Privacy (name of encryption program)
.PGP      ProGram Parameter (file name extension) [AutoCAD]
PGUP      Page Up
PHIGS     Programmers' Hierarchial Interactive Graphics
          Standards
.PHO      Phone List (file name extension)
PHS       Personal Handyphone System
PI        Program Interruption
PIA       Peripheral Interface Adapter
PIC       Personal Information Carrier +
          Personal Intelligent Communicator +
          Priority Interrupt Controller +
          Program Interrupt Controller
PICS      Platform for Internet Content Selection
PICT      Picture
PID       Process Identification Number +
          Proportional, Integral, Derivative
PIER      Procedures for Internet/Enterprise Renumbering
PIF       Picture Interchange Format File +
          Program Information File
PII       Program Integrated Information
PILOT     Programmed Inquiry Learning Or Teaching
PilotACE* Pilot Automatic Computing Engine
PIM       Personal Information Manager +
          Primary Interface Module
PIN       Personal Identification Number +
          Process Identification Number [Unix]
PINE      Pine Is Not Elm (original usage) +
          Program for Internet News & Email (present usage)
PING      Packet Internet Groper
PIO       Parallel Input/Output + Processor Input/Output +
          Programmed Input/Output
PIP       Picture In Picture + Problem Isolation Procedure +
          Programmable Interconnect Point
PIPO      Parallel In, Parallel Out
PIT       Programmable Interval Timer
PIXEL     Picture Element
PL        Plus
PLA       Programmable Logic-Array
PLATO     Programmed Logic for Automatic Teaching Operations
PLC       Programmable Logic Controller
PLCC      Plastic Leadless Chip Carrier
PLD       Programmable Logic Device
PLDS      Pilot Land Data System [NASA]
PLL       Phase Locked Loop
.PLL      Prelinked Library (file name extension) [Clipper]
PL/M      Programming Language for Micros
PLS       Primary Link Station
PLV       Production Level Video
PL/1    * Programming Language One
PM        Presentation Manager [IBM] +
          Preventative Maintenance + Process Manager
P-MAIL    Paper Mail
PMD       Packet Mode Data
PMMU      Paged Memory Management Unit
PMOS      Positive Channel Metal Oxide Semiconductor
PMR       Problem Management Report [IBM]
PMS       Policy Management System
PN        Processing Node
PNA       Programmable Network Access
PNG       Portable Network Graphics
PNP       Plug And Play
PO        Parity Odd
POC       Point Of Contact
POE       Power Open Environment
POH       Power-On Hours
POL       Problem Oriented Language
POP       Point Of Presence [MCI] + Pop from Stack +
          Post Office Protocol
POPA      Pop All Registers
POPF      Pop Flags
POR       Power-On-Reset
POS       Point Of Sale + Positive + Programmable Object Select
POSIX     Portable Operating System Interface for Unix
POST      Power-On Self Test
POSTNET   Postal Numeric Encoding Technique
POTS      Plain Old Telephone Service
POWER     Performance Optimization with Enhanced RISC [IBM]
PowerPC   Performance Optimization with Enhanced RISC-Performance
          Computing
PP        Parallel Port
.PPD      PostScript Printer Description (file name extension)
PPDS      Personal Printer Data Stream [IBM]
PPGA      Plastic Pin Grid Array
PPM       Pages Per Minute
PPP       Point-to-Point Protocol [Internet]
PPS       Packets Per Second + Power Personal Systems [IBM]
PPTP      Point-to-Point Tunneling Protocol [Microsoft]
PQFP      Plastic Quad Flat Pack
PRACSA    Public Remote Access Computer Standards Association
PRAM      Parallel Random-Access Machine +
          Parameter Random Access Memory
.PRD      Printer Driver (file name extension) [Word]
PRE       Preformatted [HTML]
PReP      Power PC Reference Platform [IBM/Motorola]
PRF       Pulse Repetition Frequency
.PRF      Preferences (file name extension) [Grammatik IV]
.PRG      Program (file name extension)
PRI       Primary-Rate Interface
PRINTF    Print with Formatting [C Programming Language]
PRISM     Photo-Refractive Information Storage Material
.PRJ      Project (file name extension) [Borland]
PRMD      Private Mangement Domain [X.400]
PRML      Partial-Response Maximum-Likelihood
.PRO      Profile (file name extension)
PROC      Procedure
PROFS     Professional Office System [IBM]
PROG      Program + Programmer
PROLOG    Programming In Logic (Programming Language)(See HLL)
PROM      Programmable Read Only Memory
PRN       Printer
.PRS      Printer (file name extension) [WordPerfect]
PRTSC     Print Screen
PS        Proportional Spacing
.PS       PostScript (file name extension)
PS/2      Programming System 2 [IBM]
PSC       Personal Super Computer + Print Server Command +
          Product Service Center
PSDN      Packet-Switched Data Network
PSDS      Packet-Switched Data Service
PSERVER   Print Server [NetWare]
PSF       Permanent Swap File
PSID      PostScript Image Data
PSM       Printing Systems Manager
PSN       Packet Switching Network
PSP       Personal Software Products (group) [IBM] +
          Program Segment Prefix
PSPDN     Packet-Switched Public Data Network
P-SRAM    Pseudo-Static Random Access Memory
PSRT      PostScript Round Table [GEnie]
PSTN      Public Switched Telephone Network
PSU       Power Supply Unit
PSW       Program Status Word
.ps.Z     Compressed PostScript (file name extension) [Unix]
PT        Page Table
P/T       Part Time
PTD       Parallel Transfer Disk Drive
PTF       Problem Temporary/Trouble Fix [IBM]
PUB       Public (directory) [Internet] + Publish
.PUB      Publication (file name extension) [Ventura]
PUN       Physical Unit Number
PUP       PARC Universal Packet (protocol)
PUS       Processor Upgrade Socket
PUSHA     Push All Registers
PUSHF     Push Flags
PVC       Permanent Virtual Circuit + Polyvinyl Chloride
PVM       Parallel Virtual Machine +
          Pass-through Virtual Machine (protocol) [IBM]
PVP       Parallel Vector Processing
PVS       Parallel Visualization Server
PW        Password
PWB       Printed Wire Board +
          Programmer's Workbench [Microsoft]
PWD       Print Working Directory [Unix]
PWR       Power
PWSCS     Programmable Workstation Communication Services [IBM]
.PX       Primary Index (file name extension) [Paradox]

Q...

QA        Quality Assurance
QAM       Quadrature Amplitude Modulation
QBE       Query By Example
QBF       Query by Form
QBIC      Query By Image Content [IBM]
QC        Quality Control
QD        Querty/Dvorak
QDOS      Quick and Dirty Operating System
.QDI      Quicken Dictionary (file name extension) [Intuit]
.QDT      Quicken Data (file name extension) [Intuit]
QEMM      Quarterdeck Expanded Memory Manager [Quarterdeck Corp.]
QFA       Quick File Access
QFE       Quick-Fix Engineering [Microsoft]
QFP       Quad Flat Pack
QIC       Quality Information Using Cycle Time [Hewlett-Packard] +
          Quarter-Inch Cartridge
.QIF      Quicken Import File/Interchange Format (file name extension)
.QMT      Quicken Memorized List (file name extension) [Intuit]
.QNX      Quicken Indexes to Data (file name extension) [Intuit]
QOS       Quality Of Service
QPG       Quantum Phase Gate
QPSK      Quadrature Phase Shift Keying
QTC       Quicktime Conferencing [Macintosh]

R...

RA        Return Authorization
.RA       Real Audio (file name extension)
RACF      Resource Access Control Facility
RAD       Rapid Application Development
RADAR     Rights, Availabilities, Distribution Analysis
          and Reporting [Disney]
RADB      Routing Arbiter Data Base

RADSL     Rate Adaptive Digital Subscriber Line
RAG       Row Address Generator
RAID      Redundant Arrays of Independent Disks +
          Redundant Arrays of Independent Drives +
          Redundant Arrays of Inexpensive Disks
RAIS      Redundant Arrays of Inexpensive Systems
RALU      Register Arithmetic Logic Unit
RAM       Random Access Memory
RAMDAC    Random Access Memory Digital-to-Analog
          Converter [Sierra]
RAMP      Remote Access Maintenance Protocol [Internet]
RAND      Random
RAP       Rapid Application Prototyping
RARP      Reverse Address Resolution Protocol
RAS       Random Access Storage +
          Reader Admission System [British Library] +
          Reliability, Availability and Serviceability +
          Remote Access Service + Row Address Select
RASAPI    Remote Access Service Application Programming
          Interface [Microsoft]
.RAT      Rating (file name extension)
RAVE      Rendering Acceleration Virtual Engine [Apple Computer]
RB        Right Button (of 2 or 3 button Mouse)
RBBS      Remote Bulletin Board System
RBCS      Remote Bar Code System
RBOC      Regional Bell Operating Company
RCL       Rotate Carry Left
RCP       Remote Control Panel + Remote Copy [Internet] +
          Restore Cursor Position
RCR       Rotate Carry Right
RCS       Records Communications Switching System +
          Revision Control System [Unix]
RD        Receive Data + Remove Directory
R&D       Research and Development
RDA       Remote Database Access
RDB       Receive Data Buffer + Relational Database
RDBMS     Relational Database Management System
RDCLK     Received Timing Clock
RDO       Remote Data Object
RDP       Reliable Datagram Protocol
RDRAM     Rambus Dynamic Random Access Memory
RDSR      Receiver Data Service Request
RDTO      Receive Data Transfer Offset [IBM]
.REC      Recorder (file name extension) +
          Recreational or Entertainment Activities (Domain
          Name) [Internet]
REC.      Recreation [USENET Newsgroup Category]
.REF      Reference (file name extension)
REG       Register
REGAL     Rigid Epoxy Glass Acrylic Laminate
RELSECT   Relative Sector
REM       Remark + Remote + Ring Error Monitor
REN       Rename
REP       Repeat
REPE      Repeat while Equal
REPNE     Repeat while Not Equal
REPNZ     Repeat while Not Zero
REPZ      Repeat while Zero
REQ       Request
REREG     Re-Register
RES       Remote Execution Service + Reset + Resolution
.RES      Resource (file name extension)
RET       Resolution Enhancement Technology [HP] + Return
RETR      Retrieve
REX       Relocatable Executable
REXEC     Remote Execution
REXX      Restructured Extended Executor (language) [IBM]
RF        Radio Frequency
RFC       Request For Comments [Internet]
RFD       Request for Discussion [Internet]
RFI       Radio Frequency Interference + Request for Information
RFP       Request for Proposal
RFQ       Request for Quotation
RFS       Remote File Sharing + Remote File System
RFT       Revisable Form Text + Rich Text Format
RFU       Reserved For Future Use
RGB       Red-Green-Blue (color model)
RI        Referential Integrity + Ring Indicate
RIFF      Resource Interchange File Format [Microsoft]
RIM       Remote Installation and Maintenance [Microsoft]
RIME      RelayNet International Message Exchange
RIP       Raster Image Processor + Remote Imaging Protocol +
          Routing Information Protocol [Novell]
RIPEM     Riordan's Internet Privacy Enhanced Mail
RIPS      Raster Image Processing System
RISC      Reduced Instruction Set Computing
RIT       Raw Input Thread [Microsoft]
RJE       Remote Job Entry
RLD       Received Line Detect
RLE       Run Length Encoded
RLL       Run Length Limited
RLN       Remote LAN Node [DCA]
RLOGIN    Remote Login
RLSD      Received Line Signal Detected
RLSI    * Ridiculously Large-Scale Integration
RM        Reset Mode
RMA       Return Material Authorization +
          Return to Manufacturer Authorization
RMB       Right Mouse Button
RMDIR     Remove Directory
RMI       Remote Method Invocation [Sun]
RMON      Remote Monitor/Monitoring
RMP       Remote Maintenance Processor [IBM]
RMS       Record Management Services + Root Mean Square
RMW       Read-Modify-Write
RN        Read News [Internet]
RND       Random
RNG       Random Number Generator
RNP       Regional Network Provider
R-O       Read Only
ROB       Reorder Buffer [Intel]
ROL       Rotate Left
ROLAP     Relational On-Line Analytical Processing
ROM       Read Only Memory
ROOM      Real-Time Object-Oriented Modeling
ROP       Raster Operation + RISC Operation
ROR       Rotate Right
ROS       Read-Only Storage [IBM]
ROT       Running Object Table
RPC       Remote Procedure Call
RPG       Report Program Generator (Programming Language)
RPL       Resident Programming Language +
          Requested Privilege Level
RPN       Real Page Number + Reverse Polish Notation
RPRINTER  Remote Printer [NetWare]
RPPROM    Reprogrammable PROM
RPT       Repeat
RPQ       Request for Price Quotation
RQBE      Relational Query By Example [Fox Pro]
RR        Real Reality
RS        Radio Shack +
          Recommended Standard (as in RS-232) [EIA] +
          Record Separator + Request to Send
RSA129    (129 digit cryptographic security number named after
          its inventors: Drs. Ronald L. Rivest, Adi Shamir and
          Leonard M. Adelman)
RSAC      Recreational Software Advisory Council
RSCS      Remote Spooling Communications System
RSD       Route Server Daemon
RSH       Remote Shell
RSL       Request-and-Status Link
RSP       Required Space Character
RSPX      Remote Sequenced Packet Exchange
RST       Reset + Restart
RSTS      Resource Sharing Time Sharing [Digital]
RSVP      Resource Reservation Protocol
RSX       Real Time Resource Sharing Executive
RT        Real Time + RISC Technology + Run Time
R/T       Receive/Transmit
RTAM      Remote Terminal Access Method
RTC       Real-Time Clock
RTDM      Real-Time Data Migration
RTEL      Reverse Telnet [Internet]
RTF       Rich Text Format
RTL       Register Transfer Language/Level +
          Resistor Transistor Logic + Right-To-Left +
          Run Time Library
RTM       Response Time Monitor + Runtime Manager [Borland]
RTMP      Routing Table Maintenance Protocol
RTOS      Real-Time Operating System
RTP       Rapid Transport Protocol + Real-Time Protocol
RTS       Remote Takeover System + Request To Send
RTSP      Real-Time Streaming Protocol
RTTI      Runtime Type Information
RTTY      Radio Teletypewriter (Communications)
RTV       Real Time Video
RVA       Relative Virtual Address
RVI       Reverse Interrupt
R/W       Read/Write
RWM       Read-Write Memory
RX        Receiver
RXD       Receive Data

S...

SA        Selective Availability
SAA       Systems Application Architecture [IBM]
SAC       Single Attachment Concentrator
SADL      Synchronous Data Link Control [Racal-Vadic]
SAINT   * Symbolic Automatic Integrator
SAL       Shift Arithmetic Left
SAM       Serial Access Memory + Sequential Access Method +
          Security Accounts Manager [Microsoft] +
          Single Application Mode [Microsoft]
SAN       System Area Network
SANE      Standard Apple Numeric Environment
SAP       Second Audio Program + Service Access Point [DEC] +
          Service Advertising Protocol +
        * Symbolic Assembly Program +
          Systems, Applications and Products (company)
SAPI      Speech Application Program Interface [Microsoft]
SAR       Segmentation and Reassembly +
          Shift Arithmetic Right +
          Successive Approximation Register +
          Synthetic Aperature Radar
SAS       Sales Accounting System + Single Attached Station +
          Single Audio System + Statistical Analysis System
SASI      Shugert Associates System Interface (SCSI originated
          from SASI)
SATAN     Security Administrator Tool for Analyzing Networks
.SAV      Saved (file name extension)
SAVDM     Single Application VDM
SB        Sound Blaster [Creative Labs] + Sound Board
SBA       Scene Balance Algorithms [Kodak]
SBB       Subtract With Borrow
SBC       Single-Board Computer
SBCS      Single-Byte Character Set
SBI       Sound Blaster Instrument
.SBR      Source Browser (file name extension) [Borland]
.SC       Script (file name extension)
SCADA     Supervisory Control and Data Aquisition
SCAM      SCSI Configuration Automatically
SCAS      Scan String
SCB       Subsystem Control Block [IBM]
SCC       Serial Communications Controllers +
          Serial Controller Chip +
          Synchronous Channel Check [IBM]
SCCS      Source Code Control System
SCD       Standard Color Display
S-CDMA    Synchronous Code-Division Multiple Access
SCF       System Control Facility
SCI       Scalable Coherent Interface
SCI.      Science [USENET Newsgroup Category]
SCLM      Softwre Configuration and Library Management [IBM]
SCM       ScreenCam Format [Lotus] +
          Software Configuration Management + Station Class Mark
SCO       Santa Cruz Operation (Software Company)
SCOPE     Simple Communications Programming Environment
          [Hayes]
SCP       Save Cursor Position + Subsystem Control Port +
          System Control Program
SCR       Silicon Controlled Rectifier
.SCR      Script (file name extension)
SCRN      Screen (video display)
SCRS      Scalable Cluster of RISC Systems
SCSA      Signal Computing System Architecture [Dialogic]
SCSI      Small Computer Systems Interface
SD        Send Data + Super Density
SDA       Software Disk Array + Source Data Automation +
          System Display Architecture [Digital]
SDB       Symbolic Debugger [Unix]
SDD       Software Description Database [Internet]
SDF       Space Delimited File + Space Delimited Format
.SDF      Standard Data Format (file name extension)
SDH       Synchronous Digital Hieararchy
SDI       Selective Dissemination of Information +
          Single Document Interface
          Software Development Interface [Mosaic]
SDK       Software Developer's Kit [Microsoft]
SDLC      Synchronous Data Link Control (protocol)
SDM       System Development Multitasking
SDMS      SCSI Device Management System [NCR]
SDN       Software Defined Network [AT&T]
SDNS      Secure Data Network Service
SDR       Streaming Data Request
SDRAM     Synchronous Dynamic Random Access Memory
SD-ROM    Super Density ROM
SDS       Sysops Distribution System
SDSL      Single-Line Digital Subscriber Line
SD_STB    Streaming Data Strobe [IBM]
SDV       Switched Digital Video [AT&T]
SDX       Storage Data Acceleration
SEA       Standard Extended Attribute [OS/2]
.SEA      Self Extracting Archive (file name extension) [Macintosh]
SEAC    * Name of first computer to use transistors, built by
          (National Bureau of) Standards Eastern Automatic
          Calculator (Also see SWAC)
SEAL      Segmentation and Reassembly Layer (protocol) +
          Screening External Access Link [Digital-DEC]
SEC       Single Error Correction
SECAM     Sequentiel Couleur Avec Memoire
          (Sequential Color With Memory)
SED       Stream Editor + Stream-Oriented Editor
SEG       Segment
SEH       Structured Exception Handling
SEL       Select
SEM       Scanning Electron Microscope +
          Standard Electronic Module
SEPP      Secure Encryption Payment Protocol
SER       Serial
SET       Secure Electronic Transaction +
          Softwave Engineering Technology
.SET      Driver Set (file name extension) [Lotus 1-2-3] [LDC] +
          Image Settings (file name extension) [Paradox]
SETEXT    Structure Enhanced Text [Internet]
SEU       Smallest Executable Unit
SF        Sign Flag
SFD       Start Frame Delimiter
SFQL      Structured Full-text Query Language
SFS       System File Server
SFT       System Fault Tolerance
SFX       Sound Effect(s)
SGEN      Signal Generator + System Generator
SGDT      Store Global Descriptor Table
SGI       Silicon Graphics, Inc.
SGM       Shaded Graphics Modeling
SGML      Standard Generalized Markup Language
SGR       Set Graphics Rendition
SGRAM     Synchronous Graphics RAM
S/H       Sample and Hold
SHA       Secure Hash Algorithm [NSA]
SHAR      Shell Archive
SHED      Segmented Hypergraphic Editor
SHG       Segmented Hypergraphics
SHL       Shift Logical Left
SHR       Shift Logical Right
S-HTTP    Secure Hypertext Transfer Protocol
.SHW      Show (file name extension)
SI        Shift-In + Source Index + System Information +
          System Integration
SIC       Standard Industrial Code
SID       Security Identifier + Serial Input Data +
          Station Identification [AT&T] +
          Symbolic Interactive Debugger
SIDF      System Independent Data Format
SIDH      System Identification for Home Systems
SIDT      Store Interrupt Descriptor Table
SIFT      Stanford Information Filtering Tool
SIG       Special Interest Group
SIGCAT    Special Interest Group on CD-ROM Applications
          and Technology
SIM       Simulator
SIMD      Single Instruction Multiple Data-stream (processor)
SIMM      Single In-line Memory Module
SIMTEL    Simulation and Teleprocessing
SIMULA    Simulation (language)
SIO       Serial Input/Output (communications driver)
SIP       Single In-line Package
SIPC      Simply Interactive Personal Computer [Microsoft]
SIPO      Serial In, Parallel Out
SIPP      Single In-line Pin Package
SIR       Serial Infrared [Hewlett-Packard]
SIRDS     Single-Image Random Dot Stereogram
SI/SO     Serial In/Serial Out + Shift In/Shift Out
SIT       Special Information Tones
.SIT      Stuff-It (compressed file name extension) [Macintosh]
SIU       System Interface Unit
SKIP      Simple Key-Management for Internet Protocols [Sun]
SKU#      Stock Keeping Unit Number
SLDT      Store Local Descriptor Table
SLED      Single Large Expensive Disk
SLIC      System Level Integration Circuit
SLIP      Serial Line Interface Protocol
SLM       Spatial Light Modulator
SLMR      Silly Little Modem Reader
SLOSH     Sea, Lake and Overland Surge from Hurricane (program)
SLSI      Super Large-Scale Integration
SLSS      Systems Library Subscription Service [IBM]
SLU       Spoken Language Understanding
SM        Set Mode + Shared Memory
SMART     Self-Monitoring Analysis and Reporting Technology
SMB       Server Message Block (protocol) [MII]
SMD       Surface Mounted Device
SMDR      Station Message Detail Recording
SMDS      Switched Multimedia/Multi-Megabit Data Service
SMF       Single Mode Fiber + System Manager Facility [Compaq]
SMI       System Management Interrupt [Intel]
SMIF      Standard Mechanical Interface
S-MIME    Secure MIME
SMIT      System Management Interface Tool [IBM]
SMK       Software Migration Kit [Microsoft]
SML       Standard Meta Language
SMM       System Management Mode [Intel]
SMOBC     Solder Mask Over Bare Copper
SMP       Simple Management Protocol + Symbolic Manipulation Program +
          Symmetrical Multi-Processing + Symmetric Multiprocessor
.SMP      Sample (file name extension)
SMPC      Shared Memory Parallel Computer
SMPS      Switching Mode Power Supply
SMRAM     System Management Random Access Memory
SMS       Small Messaging System +
          Storage Management Services [NetWare] +
          Storage Management Subsystem/System +
          Systems Management Server [Microsoft]
SMSW      Store Machine Status Word
SMT       Station Management (protocol) +
          Surface-Mount Technology
SMTP      Simple Mail Transfer Protocol
SMU       System Management Utility
SN        Serial Number
S/N       Signal-to-Noise (Ratio)
SNA       Systems Network Architecture [IBM]
SNAP      Sub-Network Access Protocol
SND       Sound
SNEWS     Secure News Server [Internet]
SNMP      Simple Network Management Protocol
SNOBOL    String Oriented Symbolic Language (Programming Language)
SNP       Serial Number/Password [Omen Technology]
SNR       Signal-to-Noise Ratio
SOA       Start Of Authority
SOC       System On a Chip
SOC.      Social Issues [USENET Newsgroup Category]
SOCKS     Socket Secure (server) [Internet]
SO-DIMM   Small Outline DIMM
SOE       Standard Operating Environment
SOH       Start of Header
SOHO      Small Office/Home Office
SOL       Simulation Oriented Language
SOM       Start of Message + System Object Model [IBM]
SONET     Synchronous Optical Network
SOP       Standard Operating Procedures
SOS       Silicon On Sapphire + Sophisticated Operating System +
          Standards and Open Systems
SOTA      State Of The Art
SOX       Sound Exchange
SP        Service Pack [IBM] + Stack Pointer + System Product
SPA       Software Publishers Association
SPAN      Space Physics Analysis Network
SPARC     Scalable Processor Architecture
SPC       Small Peripheral Controller + Statistical Process Control
SPCL      Spectrum Cellular Corporation
SPCS      Stored Program Controlled Switch
SPEC      Systems Performance Evaluation Cooperative
SPF       Shortest Path First + System Programming Facility
SPI       Security Parameters Index + Service Provider Interface +
          SCSI Parallel Interface
SPID      Service Profile/Provider Identifier
SPIKE     Science Planning Intelligent Knowledge-Based
          Environment [STScI]
SPIRES    Stanford Public Information Retrieval System
          [Stanford University]
SPL       Spooler + System Programming Language [HP]
.SPL      Spell Checker (file name extension)
SPM       System Performance Monitor [IBM]
SPOOL     Simultaneous Peripheral Operations On Line
SPOT      Shared Product Object Tree [IBM]
SPP       Sequenced Packet Protocol
SPPS      Scalable Power Parallel System [IBM]
SPR       Special Purpose Register + Statistical Pattern Recognition
SPREAD  * Systems Programming, Research, Engineering
          and Development [IBM]
SPS       Standby Power System
SPSS      Statistical Package for the Social Sciences
SPT       Sectors Per Track
SPX       Sequenced Packet Exchange [Novell]
SQ        Squeezed (files)
SQE       Signal Quality Error (test)
SQL/DS    Structured Query Language/Data System [IBM]
SQRT      Square Root
SR        Shift Register
SRAM      Shadow Random Access Memory +
          Static Random Access Memory
SRAPI     Speech Recognition API
SRB       Source-Route Bridge
.SRC      Source (file name extension)
SRD       Screen Reader System
SRDRAM    Self-Refreshed DRAM
SRGB      Sustained RGB (values)
SRM       Security Reference Monitor
SRO       Sharable and Read Only
SRP       Suggested Retail Price
.SRP      Script (file name extension)
SRPI      Server-Requester Programming Interface
SRQ       Service Request
SRR       Serially Reusable Resource
SRS       Sound Retrieval System
SS        Stack Segment + Single Sided + Seconds
SSA       Serial Storage Architecture
SSAP      Source Service Access Point
SSCP      Systems Service Control Point [IBM]
SSD       Solid State Disk
SSEC    * Selective Sequence Electronic Calculator [IBM]
SSGA      System Suppport Gate Array
SSI       Server Side Includes + Single System Image +
          Small Scale Integration
SSL       Secure Sockets Layer
SSPI      Security Service Provider Interface [Microsoft]
SSRP      Simple Server Redundance Protocol [Cisco]
SST       Spread-Spectrum Technology +
          Systems Services and Technology
STA       Spanning Tree Algorithm
STAR      Self Defining Text Archival
STB       Strobe
STC       Set Carry Flag
STD       Set Direction Flag + Standard
STDA      StreetTalk Directory Assistance [Banyan]
STDAUX    Standard Auxillary
STDERR    Standard Error
STDIN     Standard Input
STDIO.H   Standard Input/Output Header [C Programming Language]
STDM      Statistical Time Division Multiplexer
STDOUT    Standard Output
STDPRN    Standard Printer
STEP      Standard for Exchange of Product
.STF      Structured File (file name extension) [Lotus Agenda]
STI       Set Interrupt Flag
S/TK      Sectors Per Track
STL       Standard Template Library
STN       Super-Twist Nematic
.STORE    Businesses Offering Goods (Domain Name) [Internet]
STOS      Store String
STP       Secure Transfer Protocol + Shielded Twisted Pair (cable) +
          Signal Transfer Point + Synchronized Transaction Processing
STR       Store Task Register + Synchronous Transmitter Receiver
STRESS    Structural Engineering System Solver (Programming
          Language)
STRUDL    Structural Design Language (Programming Language)
STScI     Space Telescope Science Institute
STT       Secure Transaction Technology [Microsoft]
STX       Start of Text
.STY      Style (file name extension) [Ventura, Word, WordPerfect]
SUB       Subroutine + Substitute + Subtract
SUN       Sun Microsystems, Inc.
.SUP      Supplemental Dictionary (file name extension)
          [WordPerfect]
SVC       Switched Virtual Circuit
SVF       Simple Vector Format
SVGA      Super Video Graphics Array
S-VHS     Super VHS
SVM       System Virtual Machine [Microsoft]
SVN       Switched Virtual Network [IBM]
SVR       Server
SVR#      System V Release Number [AT&T]
S/W       Software
SWAC    * Mobile version of SEAC, built for deployment to White Sands,
          and named Standards Western Automatic Calculator
SWAIS     Simple Wide Area Information Server [Internet]
SWISH     Simple Web Indexing System for Humans
SWP       Simple Web Printing
.SWP      Swap (file name extension)
.SYL      Syllabus (file name extension)
SYLK      Symbolic Link
.SYM      Symbols (file name extension)
.SYN      Synonym (file name extension)
SYNC      Synchronous
SYS       System
.SYS      System Configuration (file name extension) +
          System Device Driver (file name extension)
SYSADMIN  System Administrator
SYSGEN    System Generator
SYSLOG    System Log
SYSMOD    System Modification
SYSOP     System Operator
SYSREQ    System Request
SZ        Send ZModem [Unix]

T...

TACS      Total Access Communication System
TAD       Telephone Answering Device
TAP       Telelocator Alphanumeric Protoco
TAPCIS    The Access Program for the CompuServe
          Information Service
TAPI      Telephony Applications Programming Interface
.tar      Tape Archive (archived file name extension) [Unix]
.tar.Z    Compressed Archived files (file name extension) [Unix]
TAS       Telephone Access Server
TASM      Turbo Assembler [Borland]
TAXI      Transparent Asynchronous Transceiver/Receiver Interface
TB        Terabyte (1,024 gigabytes)
T/B       Top and Bottom
TBBS      The Bread Board System (BBS)
TBGA      Tape Ball Grid Array
.TBK      Toolbook (file name extension)
TBU       Tape Backup Unit
TC        Test Control + Transmission Control
TCL       Tool Command Language
TCM       Trellis-Coded Modulation
TCP/IP    Transmission Control Protocol/Internet Protocol
TD        Transmit Data
TDD       Telecommunications Device for the Deaf
TDtoDP    Tablet Coordinates to Display Coordinates
          (converting)
TDE       Terminal Display Editor
.TDF      Trace Definition File (file name extension) [OS/2] +
          Typeface Definition File (file name extension)
TDI       Transport Device Interface
TDM       Technical Document Management +
          Time Division Multiplexing
TDMA      Time Division Multiple Access
TDMS      Terminal Display Management System
TDP       Tag Distribution Protocol [Cisco] +
          Telelocator Data Protocol
TDSR      Transmitter Data Service Request
TDR       Time Domain Reflectometry
TE/2      Terminal Emulator/2 [Oberon]
TEB       Thread Environment Block
TEC       Tokyo Electronics Corporation
TED       Tiny Editor
TEI       Terminal Endpoint Identifier
TELCO     Telephone Company
TEML      Turbo Editor Macro Language [Borland]
TEMP      Temporary
TER       Thermal Eclipse Reading [Sony]
TERMPWR   Terminator Power
TFDD      Text File Device Driver
TFEL      Thin-Film Electroluminescent
.TFM      Tagged Font Metric (file name extension)
TFT       Thin-Film Transistor (screens)
TFTP      Trivial File Transfer Protocol
THD       Total Harmonic Distortion
.THD      Thread (file name extension)
THOMAS    The (U.S.) House (of Representatives) Open Multimedia
          Access System
THOR      Tandy High-Performance Optical Recording
THR       Transmit Holding Register
.THS      Thesaurus (file name extension)
TI        Texas Instruments, Inc.
TIA       Telecommunications Industry Association +
          The Internet Adapter [Internet]
TID       Target ID
TIES      Time Independent Escape Sequence
.TIF      Tagged Image File (filename extension)
TIFF      Tagged Image File Format
TIGA      Texas Instruments Graphics Architecture
TIGER     Topologically Integrated Geographic Encoding
          and Referencing
TIIAP     Telecommunications and Information Infrastructure
          Assistance Program [NII]
TIM       Technical Information Memo [Compaq]
TIMEZONES AST - Atlantic Standard Time
          AHD - Alaska-Hawaii Daylight
          AHS - Alaska-Hawaii Standard
          BST - British Summer Time
          CDT - Central Daylight Time
          CST - Central Standard Time
          EAD - Eastern Australia Daylight
          EDT - Eastern Daylight Time
          EMT - Eastern Mediterranean
          EST - Eastern Standard Time
          JST - Japanese Standard Time
          MDT - Mountain Daylight Time
          MST - Mountain Standard Time
          MTS - Moscow Time Standard
          MTD - Moscow Time Daylight
          PDT - Pacific Daylight Time
          PST - Pacific Standard Time
          WED - Western Europe Daylight
          WES - Western Europe Standard
          YDT - Yukon Daylight Time
          YST - Yukon Standard Time
TIMI      Technology Independent Machine Interface [IBM]
TIMS      Text Information Management Systems
TINA      Telecommunication Information Networking Architecture
TIP       Terminal Interface Processor
TK/TK     Track to Track
TLA       Three-Letter Acronym
TLB       Translation Lookaside Buffer
.TLB      Table (file name extension)
TLD       Top Level Domain
TLI       Transport Layer Interface
TLU       Table Lookup
.TLX      Telex (file name extension)
TM        Trademark
.TML      Template (file name extension)
TMP       Temporary
TN        Twisted Nematic
TNC       Terminal Node Controller
TNO       The Netherlands Organization
ToC       Table Of Contents
TOD       Time Of Day
TOP       Technical and Office Protocol
TPC       Transaction-Processing Performance Council
TPF       Transactions Processing Facility [IBM]
TPI       Tracks Per Inch
TPL       Table Producing Language +
          Transaction Processing Language
TPM       Transactions Per Minute
TPORT     Twisted Pair Port Transceiver [AT&T]
TPS       Transactions Per Second +
          Transaction Processing System
TPW       Turbo Pascal for Windows
TQFP      Thin Quad Flat Pack
TQM       Total Quality Management
TR        Terminal Ready
T/R       Transmit/Receive
TRADIC  * Transistorized Airborne Digital Computer
          (Name of first computer to be entirely
          transistorized)
.TRM      Terminal (file name extension)
TRN       Threaded Read News [Internet] + Token Ring Network
TRON      The Real-Time Operating System Nucleus
TS        Top Secret
TSA       Target Service Agent + Technical Support Alliance
TSAPI     Telephony Services Application Program
          Interface [AT&T + Novell]
TSB       Termination Status Block
TSE       The Semware Editor
TSO       Time Sharing Option
TSR       Terminate and Stay Resident
TSS       Task State Segment + Time Sharing System
TS/SI     Top Secret/Sensitive Information
.TST      Test (file name extension)
TSTN      Triple Supertwisted Nematic
TSV       Tab Separated Values
TT        Typewriter Text
TTA       Transport-Triggered Architecture
TTCN      Tree and Tabular Combined Notation
.TTF      TrueType Font (file name extension)
TTL       Transistor-Transistor Logic
TTP       Thermal-Transfer Printing
TTS       Text-To-Speech + Transaction Tracking System
TTY       Teletype
TUCOWS    The Ultimate Collection of Winsock Software
TUI       Text-Based User Interface [WordPerfect]
TUMS      Table Update and Management System [Stanford University]
.TUT      Tutorial (file name extension)
TVF       Table of contents Verbosely from File [UNIX]
TVFS      Toronto Virtual File System [IBM]
TVI       Television Interference
TVOL      Television On-Line
TWAIN     Technology Without Any Interesting Name
          (connection between application and scanner software)
TWX       Teletypewriter Exchange Service
TXD       Transmit Data
.TXF      Tax Exchange Format (file name extension)
TXT       Text
TXT2STF   Text To Structured File [Lotus Agenda]
TZ        Time Zone [Unix]

U...

UA        User Agent + User Area
UAE       Unrecoverable Application Error
UAM       User Authentication Method
UART      Universal Asynchronous Receiver/Transmitter
.UC2      Compressed File (file name extension) [UltraCompressor]
UCE       Unsolicited Commercial Email
UCL       Universal Communications Language
UCS       Unicode Conversion Support + Universal Character Set +
          User Coordinate System
UCT       Universal Coordinated Time
UDC       User Defined Commands
UDE       Universal Data Exchange
UDEC    * Universal Digital Electronic Computer [Burroughs]
UDF       Universal Disk Format + User Defined Functions
UDG       User Defined Gateway
UDP       User Datagram Protocol
UDT       Uniform Data Transfer
UFS       Unix File System
UG        User Group
UI        Unix International + User Interface
UIC       User Identification Code
UID       User Identifier
UIMS      User Interface Management System
UL        Underwriters Laboratories +
          Unordered List + Upload
ULA       Uncommitted Logic Array
ULN       Universal Link Negotiation
ULSI      Ultra Large Scale Integration
UMA       Unified Memory Architecture
UMB       Upper Memory Block [LIM/AST]
UNC       Universal Naming Convention +
          Uuencoded Netnews Collator [Unix]
UNCOL     Universal Computed Oriented Language
UNI       User-Network Interface
UNICOM    Universal Integrated Communication (System)
UNICOS    Universal Compiler FORTRAN compatible
UNII      Unlicensed National Information Infrastructure
UNIVAC    Universal Automatic Computer
UNIX      (AT&T Bell Laboratories Operating System)
UNMA      Unified Network Management Architecture
UP        Uniprocessor
UPC       Universal Product Code
UPG       Upgrade
UPL       User Program Language
UPM       Unix Programmer's Manual +
          User Profile Management [IBM]
UPS       Uninterruptible Power Supply +
          Uninterruptible Power System
URC       Uniform Resource Characteristics +
          Uniform Resource Citation
UREP      Unix RSCS Emulation Protocol (protocol)
URI       Uniform Resource Identifier
URL       Uniform Resource Locator
URN       Uniform Resource Name/Number
US        Unit Separator
USART     Universal Synchronous-Asynchronous Reciever/Transmitter
USB       Universal Serial Bus [Intel]
USENET    User's Network [Internet]
USERID    User Identification
USOC      Universal Service Ordering Code
USQ       Unsqueezed (files)
USR       US Robotics (corporation)
USRT      Universal Synchronous Receiver/Transmitter
USSA      User Supported Software Association (United Kingdom)
UT        User Terminal
UTC       Coordinated Universal Time
UTI       Universal Text Interchange/Interface
UTP       Unshielded Twisted-Pair (cable)
UU        Uuencode/Uudecode
UUCP      Unix-To-Unix Copy Program
UUD       UUDecoding [Unix]
UUE       UUEncoding [Unix]
UUI       User-To-User Information [AT&T]
UUID      Universal Unique Identifier
UV        Ultraviolet

V...

VA        Virtual Address + Visual Age [IBM]
VAD       Value Added Dealer
VADD      Value Added Disk Driver
VADSL     Very-High-Rate Asymmetric Digital Subscriber Line
VAL       Value + Voice Application Language
.VAL      Validity Checks (file name extension) [Paradox]
VAM       Virtual Access Method
VAN       Value Added Network
VAP       Value Added Process
VAR       Value Added Reseller + Value Added Retailer + Variable
VAST      Variable Array Storage Technology
VAX/VMS   Virtual Address Extension/Virtual Memory System [DEC]
VB        Variable Block + Visual Basic [Microsoft]
VBA       Visual Basic for Applications [Microsoft]
VBE/AI    Vesa Bios Extension/Audio Interface
vBNS      Very High Speed Backbone Network Service [MCI + NSF]
VBR       Variable Bit Rate
VBRUN     Visual Basic Runtime
.VBX      Visual Basic Extension (file name extension)
VCC       Virtual Channel Connection
VCD       Virtual Communications Driver
VCI       Virtual Circuit Identifier
VCL       Visual Component Library
VCOS      Visual Caching Operating System [AT&T]
VCPI      Virtual Control Program Interface
VCR       Video Cassette Recorder
VDD       Virtual Device Driver
VDDM      Virtual Device Driver Manager
VDE       Video Display Editor + Visual Development Environment
VDISK     Virtual Disk
VDM       Virtual DOS Machine [IBM]
VDMAD     Virtual Direct Memory Access Device [Microsoft]
VDS       Virtual DMA Services
VDSL      Very-High-Data-Rate Digital Subscriber Line
VDT       Video Dial Tone + Video Display Terminal
VDU       Video Display Unit + Visual Display Unit
VEGA      Video-7 Enhanced Graphics Adapter [Video-7, Inc.]
VEMM      Virtual Expanded Memory Manager
VEMMI     Versatile Multimedia Interface
VER       Verify + Version
VERONICA  Very Easy Rodent-Oriented Net-Wide Index to
          Computer Archives [Internet]
VERR      Verify Read Access
VERW      Verify Write Access
VES       Video Encoding Standard [Oracle]
VESA      Video Electronics Standards Association
VF        Virtual Floppy
VFAT      Virtual File Allocation Table [Microsoft]
V.FC      Version.First Class (communications standard)
VFD       Vacuum Fluorescent Display
VFW       Video For Windows [Microsoft]
VGA       Video Graphics Array
VGC       Video Graphics Controller
VHDL      VHSIC Hardware Description Language
VHS       Very High Speed + Video Home System +
          Virtual Host Storage
VHSIC     Very High Speed Integrated Circuit
VI        Visual Interactive (editor) [UNIX]
VIE       Virtual Information Environment
VIF       Virtual Interface + Virtual Interrupt Flag
VIM       Vendor Independent Mail +
          Vendor Independent Messaging + Video Interface Module
VIO       Video Input/Output + Virtual Input/Output
VINES     Virtual Networking System [Banyan]
ViP       Visual Programming [Lotus]
VIP       Variable Information Processing +
          Video Information Provider +
          Virtual Interrupt Pending
VIPER     Verifiable Integrated Processor for
          Enhanced Reliability
VIS       Video Information System [Tandy] +
          Visual Instruction Set [Sun] +
          Voice Information System
VJ HEADER Van Jacobsen Header (compression) [Unix]
VLAN      Virtual Local Area Network
VL-BUS    Vesa Local-Bus [VESA]
VLD       Variable-Length Decoder
VLF       Very Low Frequency
VLINK     Visited Link [HTML]
VLIW      Very Large Instruction Word
VLM       Virtual Loadable Module
VLSI      Very Large Scale Integration
VLSIPS    Very Large Scale Immobilized Polymer Synthesis
VLT       Variable List Table
VM        Virtual Machine + Virtual Memory
VMA       Virtual Memory Address
VMB       Virtual Machine Boot
VME       Versa Module Eurocard +
          Virtual Memory Environment
VMM       Virtual Machine/Memory Manager
VMOS      Vertical MOS
VMP       Virtual Modem Protocol
VMS       Virtual Memory System + Voice Message System
VMT       Virtual Memory Technique
VNA       Virtual Network Architecture
VOC       Creative Voice (format) [Sound Blaster]
VOD       Video On Demand
VOL       Volume
VOM       Volt-Ohm-Milliammeter
VOR       Visions Of Reality
VOS       Verbal/Voice Operating System
VP        Virtual Path
VPD       Virtual Printer Device + Vital Product Data [IBM]
VPDN      Virtual Private Data Network
VPDS      Virtual Private Data Service [MCI]
VPE       Video Port Extensions [Microsoft] +
          Visual Programming Environment
VPL       Virtual Programming Language
VPM       Video Port Manager
VPN       Virtual Page Number + Virtual Private Network
VPS       Voice Processing System
VPSC      Vault, Process, Structure, Configuration
VPT       Virtual Print Technology [Dataproducts]
VR        Virtual Reality + Voltage Regulated/Regulator
VRAM      Video Random Access Memory
VRE       Voltage Regulated Extended
VRM       Voltage Regulator Module
VRML      Virtual Reality Modeling Language
          (originally named Virtual Reality Markup Language)
VROOMM    Virtual Real-time Object Oriented
          Memory Manager [Borland]
.VRS      WordPerfect Graphics Driver (file name extension)
VRT       Voltage Regulation Technology [Intel]
VRU       Voice Response Unit
VS        Virtual Storage
VSAM      Virtual Storage Access Method
VSAT      Very Small Aperture Terminal
VSE       Virtual Storage Extended
VSF       Vertical Scanning Frequency
VSI       Virtual Socket Interface
VSIO      Virtual Serial Input Output
VSLI      Very Large Scale Integration
VSM       Virtual Shared Memory + Virtual Storage Management +
          Visual System Management [IBM]
VSN       Volume Serial Number
VSOS      Virtual Storage Operating System
VSYNC     Vertical Sync
VT        Vertical Tab
VTAM      Virtual Telecommunications Access Method [IBM]
VTNS      Virtual Telecommunications Network Service
VUI       Video User Interface
VUP       VAX Unit of Performance
VMS       Virtual Memory System + Voice Message System
VWB       Visual WorkBench [Microsoft]
VxD       Virtual Extended Driver [Microsoft]
.VXD      Virtual Device (file name extension) [Microsoft]
V&V       Verification and Validation

W...

W/        With
W3        (see WWW)
W3A       World Wide Web Applets
W3C       World Wide Web Consortium
W4        What-Works-With-What
WAAS      Wide Area Augmentation System
WABI      Windows Application Binary Interface [SunSoft]
WAI       Web Application Interface [Netscape]
WAIS      Wide Area Information Server
WAITS     Wide Area Information Transfer System
WAN       Wide Area Network
WATS      Wide Area Telecommunications Service
.WAV      Waveform Audio (file name extension)
WBEM      Web-Based Enterprise Management
WC        Word Count
WCS       World Coordinate System
WDL       Windows Driver Library [Microsoft]
WDM       Wavelength Division Multiplexing
WDRAM     Windows Dynamic Random Access Memory
.WEB      Entities Emphasizing the WWW (Domain Name) [Internet]
WebNFS    Web Network File System [Sun]
WELL      Whole Earth 'Lectronic Link (BBS)
WFM       Wired For Management [Intel]
WFW       Windows For Workgroups [Microsoft]
WGS       Work Group System
WHAM      Waveform Hold and Modify [Microsoft]
WHC       Workstation Host Connection
WINE      Windows Emulator
WINForum  Wireless Information Networks Forum
WINS      Windows-Internet Naming Service [Microsoft]
WINSOCK   Windows Open Systems Architecture [Microsoft] +
          Windows Sockets
WINWORD   Word For Windows [Microsoft]
WISE      WordPerfect Information System Environment
WIT       Web Interactive Talk [Internet]
.WKB      Workbook (file name extension) [WordPerfect]
.WKE      Worksheet (file name extension) [Lotus 1-2-3] [LDC]
.WKQ      Spreadsheet (file name extension) [BORQU]
.WKS      Worksheet (file name extension) [Lotus 1-2-3] [LDC]
.WKZ      Compressed Spreadsheet (file name extension) [BORQU]
.WK1      Worksheet (file name extension) [Lotus 1-2-3] [LDC]
WL        Word Line
WMC       Workflow Management Coalition
.WMF      Windows Metafile Format (file name extension) [Microsoft]
WNIC      Wide-Area Network Interface Co-Processor
WNIM      Wide-Area Network Interface Module
W/O       Without
WORM      Write Once, Read Many
WOS       Workstation Operating System
WOSA      Windows Open Services/Systems Architecture [Microsoft]
WP        WordPerfect + Word Processing + Write Protected
.WPD      Windows Printer Description (file name extension)
.WPG      WordPerfect Graphics (file name extension)
WPHD      Write-Protect Hard Disk
.WPK      Keyboard (file name extension) [WordPerfect]
WPM       Words Per Minute
.WPM      Macro (file name extension) [WordPerfect]
WPOS      Workplace Operating System
WPS       Windows Printing System [Microsoft] +
          Workplace Shell [OS2]
WPVM      Windows Parallel Virtual Machine
.WQ1      Spreadsheet (file name extension) [BORPQU]
.WQ!      Compressed Spreadsheet (file name extension) [BORPQU]
WRAM      Windows Random Access Memory
.WRI      Write (file name extension)
WRK       Windows Resource Kit [Microsoft]
WS        WordStar + Workstation
WSAPI     Web Site Application Program Interface [O'Reilly]
WT        Write Through
WWIS      World Wide Information System [Internet]
WWW       World-Wide Web [Internet]
WYSBYGI   What You See Before You Get It
WYSIWYG   What You See Is What You Get

X...

XA        Extended Architecture + Extended Attribute
XAPIA     X.400 Application Program Interface Association
X2B       Hexadecimal to Binary [REXX]
.XBM      X-Windows Bitmaps (file name extension) (black and white)
.XPM      X-Windows Pixelmaps (file name extension) (color)
X2C       Hexadecimal to Character [REXX]
XCHG      Exchange
XCMD      External Command
XCOPY     Extended Copy
X2D       Hexadecimal to Decimal [REXX]
XDF       Extended Density Format [IBM]
XDR       Extended/External Data Representation
XFCN      External Function
XGA       Extended Graphics Array [IBM]
XID       Exchange Identifier
XIOS      Extended Input/Output System
XLAT      Translate
XLM       Excel Macro Language [Microsoft]
XMIT      Transmit
XML       Extensible Markup Language
XMM       Extended Memory Manager [LIM/AST]
XMS       Extended Memory Specification [LIM/AST]
XNS       Xerox Network System (protocol) [Xerox]
XOFF      Transmitter Off
XON       Transmitter On
XOR       Exclusive OR (Also EOR)
XPRM      Xerox Print Resources Manager [Xerox]
XRT       Extensions for Real-Time
XSMD      Extended Storage Module Drive (interface)
XSSI      Extended Server Side Includes
XTAL      Crystal
XTCLK     External Transmit Clock

Y...

YAM       Yet Another Modem [Omen Technology]
YAHOO     Yet Another Hierarchically Officious Oracle [Internet]
Y2K       Year 2000
(Y/N)?    (Asks for a YES or NO decision)
YTD       Year To Date

Z...

.z        Packed file (file name extension - using Pack/Unpack
          program)..lower case z..[Unix]
.Z        Compressed file (file name extension - using
          Compress/Uncompress program)..upper case Z..[Unix]
ZAW       Zero Administration for Windows [Microsoft]
ZBR       Zone-Bit Recording [IBM]
Z-CAV     Zoned Constant Angular Velocity
ZDL       Zero Delay Lockout
ZDS       Zenith Data Systems
ZIF       Zero-Insertion Force (socket)
ZIP       Zigzag In-Line Package +
          Zone Improvement Plan (ZIPcode)
.ZIP      Compressed File (file name extension) [PKWare]
.ZOO      Compressed File (file name extension) [Dhesi]
ZPV       Zoomed Port Video [Toshiba]
ZSL       Zero Slot LAN
~         Tilde
*         Wildcard character (asterisk)
*.*       Star-Dot-Star (represents
          Any file name.Any file name extension)
.$$$      Temporary File (file name extension)
1GL       First General Language (machine language)
286       80286 (microprocessor)
2GL       Second Generation Language (assembly language)
386       80386 (microprocessor)
3COM      3 Com Corporation (The 3 Coms are
          Computer, Communications and Compatibility)
3GL       Third Generation Language (programming language)
486       80486 (microprocessor)
4GL       Fourth Generation Language (descriptive language)
6DOF      Six Degrees Of Freedom