AA Auto Answer
AAA Authentication, Authorization and Accounting
AAB All-to-All Broadcast
AAC Advanced Audio Coding
AAL Asynchronous Transfer Mode Adaption Layer
AAM Automatic Acoustic Management
AAP Applications Access Point [DEC]
AARP AppleTalk Address Resolution Protocol
AAS All-to-All Scatter
AASP ASCII Asynchronous Support Package
AAT Average Access Time
AATP Authorized Academic Training Program [Microsoft]
.ABA Address Book Archive (file name extension) [Palm]
ABAP Advanced Business Application Programming [SAP]
ABC * Atanasoff-Berry Computer (First digital
calculating machine that used vacuum tubes)
ABEND Abnormal End
ABI Application Binary Interface
ABIOS Advanced BIOS
ABIST Automatic Built-In Self-Test [IBM]
ABLE Adaptive Battery Life Extender +
Agent Building and Learning Environment [IBM]
ABM Asynchronous Balanced Mode
ABR Available Bit Rate
ABRD Automatic Baud Rate Detection
ABRS Automated Book Request System [British Library]
ABS Address Book Synchronization [IBM] + Absolute
ABT Abort
ABTS ASCII Block Terminal Services
AC Autocheck + Automatic Computer + Alternating Current
ACAP Application Configuration Access Protocol
ACC Accumulator
ACCMAIL Accessing the Internet Via Email
ACD Automatic Call Distribution
ACDI Asynchronous Communications Device Interface
ACE Access Control Encryption/Entry +
Adobe Certified Expert +
Advanced Composition Explorer [JHUAPL] +
Advanced Computing Environment [SCO] +
Adverse Channel Enhancements [Microcom] +
* Automatic Computing Engine
ACF Access Control Field +
Advanced Communications Function
ACH Automated Clearing House
ACIAS Automated Calibration Interval Analysis System
ACIS American Committee for Interoperable Systems
ACK Acknowledgment
ACL Access Control List + Asynchronous Connection-Less (link)
ACM Association for Computing Machinery
Audio Compression Manager [Microsoft]
ACMS Application Control Management System
ACP Ancillary Control Program + Auxiliary Control Process
ACPI Advanced Configuration and Power Interface
ACR Allowed Cell Rate
ACROSS Automated Cargo Release and Operations
Service System
ACS Access + Access Control Set + Access Control System +
* Advanced Computer System [IBM] +
Anti Curl System + Asynchronous Communication Server
ACSS Audio Cascading Style Sheets
ACTLU Active Logical Unit
ACTPU Active Physical Unit
ACTS Automated Computer Time Service
ACTT Advanced Communication and Timekeeping Technology [Seiko]
ACU Automatic Calling Unit
ACVC Ada Compiler Validation Capacity
A/D Analog to Digital
ADA Automatic Data Acquisitions +
(Programming Language named after Augusta Ada Lovelace)
ADB Apple Desktop Bus
ADC Adaptive Data Compression (protocol) [Hayes] +
Add with Carry + Analog to Digital Converter
ADCCP Advanced Data Communication Control Procedures/Protocol
ADD Automatic Document Detection [WordPerfect]
ADF Automatic Document Feeder +
Automatically Defined Function
.ADF Adapter Description File (file name extension)
ADI AutoCad/AutoDesk Device Interface (driver)
ADIOS Automated Download and Installation of
Operating Systems [Queensland U.]
ADL Address Data Latch
ADLAT Adaptive Lattice Filter
ADLC Adaptive Lossless Data Compression [IBM] +
Asynchronous Data Link Control
ADMACS Apple Document Management And Conrol System
ADMD Administrative Management Domain [X.400]
.ADN Add In Utility (file name extension)
[Lotus 1-2-3] [LDC]
ADO ActiveX Data Objects
ADP AOLserver Dynamic Pages + Automatic Data Processing
ADPCM Adaptive Differential Pulse Code Modulation
ADR Address
ADS Application Development Solutions [AT&T] +
Application Development System +
Automatic Distribution System
ADSC Address Status Changed +
Adobe Document Structuring Conventions
ADSI Active Directory Service Interface [Microsoft] +
Analog Display Services Interface
ADSL (See DSL)
ADSP AppleTalk Datastream Protocol
ADSR Attack, Decay, Sustain, Release
ADT Abstract Data Type + Application Data Types
ADU Automatic Dialing Unit
AE Above or Equal
AEB Analog Expansion Bus [Dialogic]
AEC Architecture, Engineering, Construction
AEM Asynchronous Event Mechanism
.AERO Aviation Industry (Domain Name) [Internet]
AES Advanced Encryption Standard
AESA ATM End System Address
AF Auxiliary carry Flag
AFA Accelerated File Access
AFC Antiferro-Magnetically Coupled (media) [IBM] +
Automatic Font Change + Automatic Frequency Control
AFD Automatic File Distribution
AFDW Active Framework for Data Warehousing [Microsoft]
AFI Authority and Format Identifier
AFII Association for Font Information Interchange
AFIRM Automated Fingerprint Image Reporting and Match
AFIS Automated Fingerprint Identification System
.AFM Adobe Font Metrics (file name extension) [Adobe Systems]
AFP Advanced Function Presentation [IBM] +
Advanced Function Printing +
Appletalk Filing Protocol [Macintosh]
AFS Andrew File System (protocols)
AFTP Advanced/Anonymous File Transfer Protocol
AGA Advanced Graphics Adapter
AGC Automatic Gain Control
AGP Accelerated/Advanced Graphics Port
AGRAS Antiglare-Antireflective-Antistatic
AGU Address-Generation Unit
AH Authentication Header (protocol)
AHS Automated Highway Systems
AI Analog Input + Artificial Intelligence
AIA Applications Integration Architecture [DEC]
AIC AIXwindows Interface Composer [IBM]
AIFF Audio Interchange File Format
AIIM Association for Information and Image Management
AIM AOL Instant Messenger
AIN Advanced Intelligent Network [Bell Atlantic]
AIO All-In-One
AIP Application Infrastruture Provider
AIR Architecture Implementation Review
AIS Automated Identification System [NCIC] +
Automated Information Systems
AISB Association of Imaging Service Bureaus
AISP Association of Information Systems Professionals
AIT Advanced Intelligent Tape (drive) [Sony]
AIX Advanced Interactive Executive [IBM]
AJAX Asynchronous JavaScript and XML
ALAT Advanced Load Address Table
ALC Arithmetic and Logic Circuits +
Automatic Level Control
ALE Address Latch Enable +
Application Linking and Embedding
ALGOL Algorithmic Oriented Language (see IAL)
ALIBI Adaptive Location of Internetworked Bases
of Information
ALICE Artificial Linguistic Internet Computer Entity
ALINK Active Link [HTML]
ALIWEB Archie Like Indexing in the Web [Internet]
ALM Asset Liability Management
ALN Asynchronous Learning Network
ALOS Alternate Lighting Of Surfaces
ALP Automatic Language Processing
ALR Advanced Logic Research, Inc.
ALT Alternate (mode)
ALT. Alternate lifestyle [USENET Newsgroup Category]
ALU Arithmetic Logic Unit
AM Amplitude Modulation
AMA Automatic Message Accounting
AMANDDA Automated Messaging and Directory Assistance
AMASS Archival Management and Storage System
AMD Active Matrix Display + Advanced Micro Devices, Inc.
AMDD Agile Modelling Driven Development
AMI Alternate Mark Inversion + American Megatrends, Inc. +
Application Messaging Interface
AMMA Advanced Memory Management Architecture [Everex Systems]
AMPL Algebraic/Applied Mathematical Programming Language
AMPS Advanced Mobile Phone Service + Amplifiers
AMR Audio Modem Riser
ANCOVA Analysis of Covariance
ANDF Architecture-Neutral Distribution Format
ANI Automatic Number Identification
.ANI Animated Cursor (file name extension) [Microsoft]
ANN Artificial Neural Network
.ANN Annotations (file name extension) [IBM]
ANOVA Analysis Of Variance
ANSI American National Standards Institute
ANX Automotive Network Exchange [Chrysler/Ford/
General Motors]
AO Analog Output
AOCE Apple Open Collaboration Environment
AO/DI Always On/Dynamic ISDN
AODV Ad Hoc On-Demand Distance Vector
AOE Application Operating Environment [AT&T]
AOL America Online
AOS Add Or Subtract
AP Adjunct Processor + Application Processor
A/P Accounts Payable
APA Adaptive Packet Assembly +
All Points Addressable +
Arithmetic Processing Accelerator
APAR Authorized Program Analysis Report [IBM]
APAREN Address Parity Enable [IBM]
APCUG Association of PC User Groups
APDU Application Protocol Data Units
API Application Program Interface
APIC Advanced Programmable Interrupt Controller (bus) [Intel]
APIPA Automatic Private Interenet Protocol Addressing
APIS Advanced Passenger Information System
APL * A Programming Language (Mathematics)
APM Advanced Power Management [IBM]
APNIC Asia-Pacific Network Information Center [Internet]
APOP Authenticated Post Office Protocol
.APP Application (file name extension) [R:Base]
APPC Advanced Program-to-Program Communications [IBM]
APPI Advanced Peer-to-Peer Internetworking
APPLETS Applications
APPN Advanced Peer-to-Peer Networking [IBM]
APPS Applications
APR Annual Percentage Rate
APRP Adaptive Pattern Recognition Processing
APS Active Pixel Sensor + Advanced Photo System +
Advanced Printing Service [IBM] +
Asynchronous Protocol Specification
APSE ADA Programming Support Environment
APT Address Pass Through +
Advanced Parallel Technology +
Automatically Programmed Tools
A/R Accounts Receivable
ARA AppleTalk Remote Access
ARAG Antireflective-Antiglare
ARAS Antireflective-Antistatic
ARC Acoustic Resonance Control
.ARC Archive (file name extension)
ARCA Advanced RISC Computing Architecture
ARCnet Attached Resource Computer Network
.ARJ Compressed File (file name extension) [Jung]
ARL Adjusted Ring Length
ARLL Advanced Run Length Limited
ARM Advanced RISC Machine (processor) +
Annotated Reference Manual +
Asynchronous Response Mode
ARMA Association of Records Managers and Administrators
ARP Address Resolution Protocol [Novell]
ARPANET Advanced Research Projects Agency Network
ARPL Adjust Requested Privilege Level
ARS Activity Reporting System [Unisys]
ART Adaptive Resonance Theory (algorithm)
ARTA Apple Real Time Architecture
ARTIC A Real-Time Interface Coprocessor [IBM]
ARTS Asynchronous Remote Takeover Server
.ARTS Cultural Groups (Domain Name) [Internet]
ARTT Asynchronous Remote Takeover Terminal
ARQ Automatic Repeat Request
ARU Audio Response Unit + Average Retail Value
AS Autonomous System [Internet]
ASAI Adjunct Switch Application Interface [AT&T]
ASAP As Soon As Possible +
Automatic Switching And Processing
AS3AP ANSI SQL Standard Scalable and Portable
ASB Advanced System Buffering [Intel]
.ASC ASCII text (file name extension)
ASCC * Automatic Sequence Controlled Calculator [IBM]
ASCII American Standard Code for Information Interchange
ASD Application Structure Database [Microsoft] +
Automatic Skip Driver [Microsoft]
ASF Active Streaming Format [Microsoft] +
Advanced Systems Format [Microsoft]
ASIC Application-Specific Integrated Circuit
ASIT Advanced Security and Identification Technology
ASL Adaptive Speed Levelling
ASLM Apple Shared Library Manager [Macintosh]
.ASM Assembler Source Language (file name extension)
ASMP Asymmetric Multprocessing
ASN Abstract Syntax Notation + Autonomous System Number
ASO Automated Systems Operations
ASP Active Server Page [Microsoft] +
Application/Authorized Service Provider +
Aspect Oriented Programming +
Association of Shareware Professionals
.ASP Active Server Page (file name extension)
ASPI Advanced SCSI Programming Interface [Adaptec]
ASPS Advanced Signal Processing System
ASR Address Space Register + Automatic Send-Receive +
Automatic Speech Recognition +
Automatic System Recovery
ASSP Anti-Spam SMTP Proxy +
Application-Specific Standard Product
AST AST Research, Inc. (named from first initials of
the founders: Albert Wong, Safi Qureshey, Thomas Yuen)
AS/U Advanced Server for Unix
ASYNC Asynchronous
AS/400 Application System/400 [IBM]
AT Advanced Technology + Attention
ATA Advanced Technology Attachment +
Analog Terminal Adapter
ATAPI Advanced Technology Attachment Packet Interface
ATC Advanced Transfer Cache
ATDP Attention Dial Pulse
ATDT Attention Dial Tone
ATE Automated Test Equipment
ATG Advanced Technology Group
ATH Attention Hang-Up (Modem command)
ATL Active Template Library
ATM Adobe Typeface Manager + Air Traffic Management +
Asynchronous Transfer Mode + Automated Teller Machine
ATPS AppleTalk Printing Services [Macintosh]
ATR Automatic Terminal Recognition
ATS Administrative Terminal System +
Apple Terminal Services
AT&T American Telephone and Telegraph
ATTN Attention
ATTRIB Attribute (also ATR)
ATX Advanced Technology Extended [Intel]
ATZ Attention Restore configuration profile from
nonvolatile RAM (Modem command)
.AU Audio (file name extension)
AUDIT Automated Data Input Terminal
AUI Attachment/Autonomous Unit Interface
AUP Acceptable Use Policy [Internet]
AUTO Automatic
AUTOEXEC Automatic Execution
AUX Auxiliary + (First Serial Port)
AV Audio/Video + Audio/Visual + Authenticity Verification
AVA Audio Visual Authoring [IBM]
AVC Audio Visual Connection [IBM]
AVD Alternating Voice and Data
AVG Average
AVI Audio Video Interleave [Microsoft]
AVL AVL Tree (named after its founders:
Adelson, Veiskii and Landis
AVP Attribute-Value Pair
AVR Automatic Voice Recognition
AVS Advanced Visual Systems
AVT Applied Voice Technology
AVVID Architecture for Voice Video & Integrated Data [Cisco]
AWE Advanced Wave Effects [Creative Lab]
AWG American Wire Gage
AWK (Unix language named after its authors...
Al Aho, Peter Weinberger and Brian Kernighan)
AWS Advanced Workstations and Systems (group) [IBM]
AWT Abstract Window Toolkit [Java]
AX Architecture Extended + Automatic Transmission

BA Bell Atlantic (company)
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
BAPI Business Application Programming Interface [SAP]
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)
B2B Business-To-Business
BBS Bulletin Board System
B2C Business To Consumer
BCC Block Check Character
BCC: Blind Carbon Copy
BCD Binary Coded Decimal
B-CHANNEL Bearer Channel
BCL Base Class Libraries + Batch Command Language
BCN Beacon
BCNF Boyce-Codd Normal Form
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 (See DSL)
BE Below or Equal
B2E Business To Employees
BECN Backward Explicit Congestion Notification
BEDO Burst Extended Data Out
BEEP Blocks Extensible Exchange Protocol
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
.BFC Briefcase (file name extension) [Microsoft]
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
BHO Browser Helper Object [Spybot]
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
BIW Business Intelligence Warehouse [SAP]
BIX Byte Information Exchange (BBS)
.BIZ Businesses (Domain Name) [Internet]
.BK! Backup (file name extension) [WordPerfect]
.B~K Backup (file name extension)
BKSP Backspace
BL Backlit + Bit Line
BLAS Basic Linear Algebra Subroutines
BLAST Bell Labs Layered Space Time +
Blocked Asynchronous Transmission (protocol)
[Communications Research Group]
.BLD BASIC Bload Graphics (file name extension)
BLE Branch if Less or Equal
BLER Block Error
BLI Business Logic Integration [Microsoft]
BLK Block
BLMC Buried Logic Macrocell
BLOB Binary Large Object
BLOG Web Log
BLOS Branch if Lower Or Same
BMI Branch if Minus
BMIC BusMaster Interface Controller [Intel]
BMP Basic Mapping Support + Basic Multilingual Plane +
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) +
British Naval Connector
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
BOA Basic Object Adapter
BOB Break-out Box
BOC Basic Operator Console
BOF Beginning Of File
BOM Basic Online Memory [IBM] + 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
Berkeley Packet Filter
BPI Bits Per Inch
BPL Branch If Plus + Broadband Over Power Lines
BPM Business Process Management [Microsoft]
BPP Bits Per Pixel
BPR Business Process Re-engineering [Linux]
BPS Bits Per Second + Bytes Per Second
BPSK Binary Phase Shift Keying
BR Bad Register
BRGC Binary Reflected Gray Code
BRI Basic Rate Interface + Brain Response Interface
BS Backspace
BSAM Basic Sequential Access Method
BSC Base Station Controller + 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
BSM Basic Storage Module [IBM]
BSP Bulk Synchronous Parallelism
BSR Bit Scan Reverse
BS-RAM Burst Static RAM
BSS Block Started by Symbol
BST Binary Search Tree
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
BTI Business Type Identifier
BTOA Binary To ASCII
BTP Batch Transfer Program
BTR Bit Test and Reset
BTS Base Transceiver Station + 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 Programming Language
.C C source code (file name extension) [C]
CA Certification Authority + Collision Avoidance
CAB Compressed Application Binary [Microsoft]
.CAB Cabinet (file name extension) [Microsoft]
CACLS Command-Line Access Control Lists [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
CAEN Chemically Assembled Electronic Nanocomputer
CAEX Computer Aided Exploration
CAG Column Address Generator
CAI Computer Aided Instruction
CAIRN Collaborative Advanced Interagency Research Network
CAL Calendar + Client Access License +
Computer Aided Learning
CALS Computer-Aided Acquisition in Logistic Support
CAM Common Access Method + Computer Aided Manufacturing +
Contents Addressable Memory
CAN Cancel + Controller Area Network
CANBUS Conroller Area Network Bus
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]
CAPE Concurrent Art-to-Product Environment
CAPS Capitals (Upper Case Letters) +
Cassette Programming System
CAPTCHA Completely Automatic Public Turing Test To Tell
Computers and Humans Apart
CAR Committed Access Rate [Cisco]
CARL Colorado Alliance of Research Libraries [Internet]
CART Computer-Assisted Radar Tomography
CAS Column Address Select/Strobe +
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
CAT5E (Cat 5e) Category 5e (cables)
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
CAVE Computer Automatic Virtual Environment
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\Instrumentation
CBL Computer Based Learning
.CBL COBOL source code (file name extension)
CBMS Computer-Based Mail System
CBN Community Based Networks
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 + Copy Control Information
CCIE Cisco Certified Internetwork Expert [Cisco]
CCITT Comite Consultatif International Telegraphique et
Telephonique/ Consultative Committee for International
Telegraph and Telephone
CCL Connection/Cursor Control Language
CCM Corba Component Mode + Crystal Configuration Manager [Microsoft]
CCNA Cisco Certified Network Associate
CCNP Cisco Certified Network Professional
CCP Certified Computing Professional +
Console Command Processor
CC/PP Composite Capabilities/Preference Profile
CCS Common Command Set + Common Communications Services +
Common Communications Support +
Continuous Composite Servo + Cryptographic Checksum
.CCS Color Calibration System (file name extension)
CCSIS Coded Character Set ID
CCSD Cellular Circuit-Switched Data
CCTLD Country Code Top-Level Domain
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]
.CDA CD Audio-Track (file name extension)
CDBT Compact Disk-Based Training
CDC Connected Device Configuration +
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
CDO Collaboration Data Objects [Microsoft]
CDOS Concurrent Disk Operating System
CDP * Certificate In Data Processing (First certification
for Computer Professionals)
CDPD Cellular Digital Packet Data
CDR Call Detail Record + Call Detail Recording +
Common Data Representation
.CDR CorelDRAW (file name extension) [Corel]
CD-R Compact Disk - Recordable
CD-RAM Cached RAM
CD-RDX Compact Disk - Read Only Memory Data Exchange Standard
CDRL Contract Data Requirements List
CD-ROM Compact Disk - Read Only Memory
CD-ROM-XA CD-ROM Extended Architecture
CD-RTOS Compact Disk - Real Time Operating System
CD-RW Compact Disk - Rewritable
CDS Current Directory Structure
CDSA Common Data Security Architecture
CDSL (See DSL)
.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 +
Consumer Elecronics + Convert Enable
CEB Conditional End Bracket
CEC Certified E-Commerce Consultant
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 Europeen pour la Recherche
Nucleaire)
CERT Computer Emergency Response Team
CFB Cipher Feedback + Configurable Function Block
CF Compact Flash (camera)
.CFG Configuration (file name extension)
CFM Code Fragment Manager [Macintosh] +
Cubic Feet Per Minute
CFML ColdFusion Markup Language
CFP Call For Proposal
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 Computer Generated Images + Computer Graphics Interface
CGI-BIN Common Gateway Interface - Binary
.CGM Computer Graphics Metafile (file name extension) +
Graph (file name extension) [Lotus 1-2-3] [LDC]
CGMS Copy Generation Management System
CGS Continuous-Grain Silicon
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
CHIPS Clearinghouse Interbank Payments System
.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
CHTML Compact/Compressed HTML
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
CIL Common Intermediate Language [ECMA]
CIM Common Information Model +
CompuServe Information Manager +
Computer Integrated Manufacturing
CIO Chief Information Officer
CIOCS Communication Input/Output Control System
CIP Command Interface Port + Common Indexing Protocol
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 Computing
CIT Computer-Integrated Telephony
CIVR Computer and Interactive Voice Response
CIW Certified Internet Webmaster
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
CLDC Connected Limited Device Configuration
CLEC Competitive Local Exchange Carrier
CLI Call-Level Interface + Clear Interrupt Flag +
Client Library Interface + Command Line Interface +
Common Language Infrastructure/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) [Microsoft]
CLR Common Language Runtime [Microsoft]
CLS Clear Screen + Common Language Support
CLSID Class Identifier
CLTP Connectionless Transport Protocol
CLTS Clear Task Switch Flag
CLTV Constant Linear Time Velocity
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
CMAK Connection Manager Administration Kit [Microsoft]
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 Chemical Markup Language + 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 Coats-Mellon Operational Specification +
Complementary Metal-Oxide Semiconductor
CMOV Conditional Move
CMP Compare + Computer
CMPS Compare Word String
CMS Call Management Server + Code Management System +
Commercial Content Management System +
Compiler Monitor System + Conversation Monitor System
CMTS Cable Modem Termination 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/Network Administrator
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
Discovery and Retrieval [Internet]
CNN Composite Network Node
CNR Carrier to Noise Ratio + Communication Network Riser
CNSS Core Nodal Switching Subsystem [Internet]
CNT Carbon Nanotube
.CNT Contents (file name extension)
CNV Conventional (pertaining to Memory)
CNVT Convert
CNX Certified Network Expert
CO Central Office + Command Output + Convert Out
COAST Card On A Stick (module)
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
COE Common Operating Environment
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 Component Object Model [Microsoft] +
Computer Output Microfilm
.COM Command (file name extension) +
Commercial Business (Domain Name) [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
COMM Communications
COMMAT In Morse Code (.--.-.)(dot dash dash dot dash dot),
name of the sign to denote the Commercial At symbol "@".
(Adopted by the ITU in December 2003)
COMP Compare
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
.COOP Cooperatives-Business (Domain Name) [Internet]
COPICS Communications Oriented Production Information
and Control System [IBM]
COR Common Object Runtime
CORBA Common Object Request Broker Architecture
COREN Corporation for Research and Enterprise Network
COS Compatible Operating System +
Customer Order Specification [Kodak/Fuji]
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 (software)
CP Copy Protected
CPA Certified Public Accountant + Cost Per Action
CPAN Comprehensive Perl Archive Network
CPC Constant Point Calculation + Cost Per Click
CPCS Check Processing Control System [IBM]
CPE Central Processing Element +
Customer Premises Equipment +
Customer Provided Equipment
.CPE Cover Page (file name extension)
CPFR Collaborative Planning, Forecasting and Replenishment
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)
CPLD Complex Programmable Logic Device
CPM Critical Path Method + Cryptography Provider Manager
CP/M Control Program for Microcomputers [Digital Research]
CPO Chief Privacy Officer
CPRM Content Protection for Recordable Media
CPS Certification Practice Statement +
Characters Per Second + Cycles Per Second
CPT Command Pass Through
CPU Central Processing Unit
CPW Commercial Processing Workload [IBM]
CR Carriage Return
CRAM Challenge-Response Authentication Mechanism +
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
CRISM Compact Reconnaissance Imaging Spectrometer for Mars
CRISP C Reduced Instruction Set Processor [AT&T Bell Labs]
CRL Certificate Revocation List
CR/LF Carriage Return/Line Feed
CRM Customer Relationship Management
CROM Control Read Only Memory
CRT Cathode Ray Tube
CRTC CRT Controller
CRUD Create, Retrieve, Update, Delete
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 Code Sequence Identification +
Command Sequence Introducer +
CompuServe Incorporated
CSID Called Subscriber Identification
CSL Computer Sensitive Language
CSLIP Compressed Serial Line Interface Protocol [Internet]
CSM Code Set Map (file) + Communications Services Manager +
Control Strip Module [Macintosh]
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 +
Chip-Scale Packaging +
Commercial Service Provider +
Commercial Subroutine Package +
CompuCom Speed Protocol [CompuCom] +
Communicating Sequential Processes +
Cross System Product [IBM]
CSPDN Circuit Switched Public Data Network
CSRAM Custom Static RAM
CSS * Continuous System Simulator (Language)
CSS Cascading Style Sheet [Microsoft] +
Contact Start-Stop + Content Scrambling System
CSSM Client-Server Systems Management [IBM]
CS/SS Card Service/Socket Service
CSTA Computer-Supported Telephony Applications
CSU Channel Service/Switching Unit
CSV Circuit-Switched Voice +
Comma-Separated Value/Variable +
Common Services Verbs (interface) [Microsoft]
C2T Cable Changing Technology
C&T Chips and Technologies
CTB Cipher Type Byte
CTC Channel To Channel + Counter/Timer Chip
CTCP Client-To-Client Protocol
CTI Computer-Telephony Integration
CTL Complex Text Layout
CTOS Cassette Tape Operating System +
Computerized Tomography Operating System +
Convergent Technologies Operating System
CTP Community Technology Preview [Microsoft]
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 + Computer Telephony Solution [IBM] +
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
CVE Common Vulnerabilities and Exposures [US-CERT]
CVF Compressed Volume File
CVGA Color Video Graphics Array
CVIA Computer Virus Industry Association
.CVR Cover Page (file name extension)
CVS Computer Vision Syndrome + Concurrent Versions System
CVT Convert
CVW CodeView for Windows
CWA Competitive Web Analysis
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]
CXML Commerce Extensible Markup Language
CYL Cylinder
CYMK Cyan-Yellow-Magenta-Black (color model)

D/A Digital to Analog
DAA Data Access Arrangement +
Decimal Adjust for Addition
DAB Digital Audio Broadcasting
DAC Data Acquisition and Control + Device Access Code +
Digital to Analog Converter +
Dual Attachment Concentrator
DACL Discretionary Access Control List
DACTLU Deactive Logical Unit
DAD Desktop Application Director [Borland]
DAE Digital Audio Extraction
DAF Destination Address Field
DAI Distributed Artificial Intelligence
DAL Data Access Language [Apple Computer] +
Data Access Layer + Disk Access Lockout
DAM Data Acquisition and Monitoring
DAMA Demand Assigned Multiple Access
DAMPS Digital AMPS
DAO Data Access Object [Microsoft] + Disk At Once
DAP Data/Directory Access Protocol +
Developer Assistance Program +
Dynamic Application Partitioning [IBM]
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 +
Distributed Authoring and Versioning
DAVIC Digital Audio-Visual Council
dB Decibel
DB Data Base + Data Buffer + Device Bay
dBA Adjusted Decibel
.dba Date Book Archive (file name extension) [Palm]
DBBS Dynamic Bass Boot System
DBC Device Bay Controller
DBCS Delivery Bar Code Sorter + Double-Byte Character Set
.DBF Database Format (file name extension)
DBIS Dun & Bradstreet Information Services
.DBK Docbook (format) (file name extension)
dBm Decibels to a Milliwatt
DBM Data Base Manager
DBMS Data Base Management System
DBR DOS Boot Record
DBS Data Base Server +
Direct (to home) Broadcast (satellite) System
DBV Digital Broadcast Video
DBWR Database Writer [Oracle]
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 Digital Camera + Direct Chip Attach Module
DCB Device Control Block + Disk Coprocessor Board [Novell]
DCC Data Country Code + 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] +
Design Rule for Camera File Systems +
Driver Configuration File [Lotus]
D-CHANNEL Data Channel
DCI Digital Camera Images + Display Control Interface
DCIM Duscrete Complex Image Method
DCL Data Control Language + Declaration +
DEC Command Language [DEC] +
Device Clear + Digital Control Logic +
Digital Command Language [Digital]
DCML Dynamic Configuration Markup Language
DCOM Distributed Component Object Model
DCP Device Control Protocol +
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 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 +
Digital Document Interchange + 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
DDOS Distributed Denial Of Service
DDP Datagram Delivery Protocol +
Distributed Data Processing
DDR Dynamic Document Review [Symantec]
DDR-SDRAM Double Data Rate-SDRAM
DDS Data Description Specification +
Digital Dataphone Service [AT&T] + Design Data Sheet +
Digital Data Storage + Direct Digital Synthesis +
Distributed Database Services
DDX Digital Data Exchange
DE Device End
DEA Data Encryption Algorithm + Disposable Email Address
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 Directory Enabled Network +
Document Enabled Networking [Novell-Xerox]
DEP Data Execution Protection [Microsoft]
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 + Default + Destination Field +
Device Flag + Double Flag
DFC Data Flow Control
DFD Data Flow Diagram
DFDR Digital Flight Data Recorder
DFM Design For Manufacturability [IBM]
DFP Digital Flat Panel
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]
DIAD Delivery Information Acquisition Device [UPS]
DIB Device Independent Bitmap +
Directory Information Base +
Dual Independent Bus [Intel]
DIBOL DEC Business Oriented Language
.DIC Dictionary (file name extension)
DICOM Digital Imaging and Communications in Medicine
DID Direct Inward Dialing
DIDS Distributed Intrusion Detection System
DIF Data Interchange Format
DIFFSENS Differential Sense
DIIP Direct Interrupt Identification Port
DILA Direct-Drive Image Light Amplifier
DIME Direct Internet Message Encapsulation
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 Distributed Interactive Simulation +
Draft International Standard +
Dynamic Impedance Stabilization [CompuCom]
DISA Data Interchange Standards Association +
Direct Inward System Access
DISP Displacement (offset)
DIST Digital Image Scaling Technology
DIT Directory Information Tree
DIV Divide
DIVE Direct Interface Video Extension [OS/2 Warp]
DIVX Digital Video Express
DIW D-Inside Wire [AT&T]
DIX Digital-Intel-Xerox (Original Ethernet Standard)
.DIZ Description In Zip (file name extension)
DL Download (also D/L)
DL/1 Data Manipulation Language 1 [IBM]
DLB Dynamic Load Balancing
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
DLPI Data Link Provider Interface
DLR DOS LAN Requester
DLS Data Link Switching [IBM] + Downloadable Sounds
DLT Digital Linear Tape
DM Distributed Memory
DMA Direct Memory Access/Addressing +
Document Management Alliance
DMAC DMA Controller
DMACS Distributed Manufacturing Automation & Control Software
DMD Digital Micromirror Device [TI]
DME Direct Memory Execution +
Distributed Management Environment
DMF Distribution Media Format [Microsoft]
DMI Desktop Management Interface
DML Data Manipulation Language +
Dialog Markup Language [W3C]
DMM Digital Multimeter
DMMS Dynamic Memory Management System
DMOS Double-diffused Metal-Oxide Semiconductor
DMP Dot Matrix Printer
DMPC Distributed Memory Parallel Computer
DMPP Distributed Memory Parallel Processor
DMQS Display Mode Query and Set [IBM]
DMS Data Management Software + Data/Document
Management System
DMSD Digital Multistandard Decoding
DMSDK Digital Media Software Development Kit [SGI]
DMSS Distributed Mass Storage System
DMT Digital/Discrete Multi-Tone
DMTF Desktop Management Task Force
DMY Day Month Year
DMZ Demilitarized Zone
DN Down
DNA Deoxyribonucleic Acid
DNC Direct Numerical Control
DNIC Data Network Identification Code
DNIE Digital Natural Image Engine
DNIS Dialed Number Identification Service
DNS Domain Naming System
DO Data Out + Distributed Objects
DOA Dead On Arrival
.DOC Document + Documentation (file name extensions)
DOCSIS Data Over Cable-Service Interface Specification
DOCSV Data Over Circuit-Switched Voice
DOE Distributed Objects Environment/Everywhere
DOIP Dial Other Internet Providers [IBM]
DO-IT Disabilities, Opportunities, Internetworking and
Technology
DOLAP Desktop OLAP
DOM Document Object Model [W3C]
DOMF Distributed Object Management Facility
DOS Denial Of Service + Disk Operating System
DOSEM DOS Emulation
.DOT Document Template (file name extension)
DOV Data Over Voice
DOW Day Of Week
DP Data Processing + Dot Pitch
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 Digital Power Management Signaling +
Display Power Management Support
DPO Data Phase Optimization
DPOF Digital Print Order Format
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]
DRCMF Digital Reality Creation Multi Function [Sony]
DRDA Distributed Relational Database
Algorithm/Architecture [IBM]
DR-DOS Digital Research-Disk Operating System
DRDW Direct Read During Write
DRE Direct Recording Electronic (voting systems)
DRI Declarative Referential Integrity +
Digital Research Incorporated
DRM Digital Rights/Distributed Resource Management
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
DS3 Digital Signal Level 3
DSA Digital Signature Algorithm + Directory System Agent
DSAP Destination Service Access Point
DSD Direct Stream Digital [Sony-Philips]
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)
DSIG Digital Signature
DSIS Distributed Support Information Standard
DSL Digital Subscriber Line
ADSL Asymmetric DSL
BDSL Broadband DSL
CDSL Consumer DSL [Rockwell]
FDSL Fixed Directory Subscriber List
HDSL High-Bit-Rate DSL +
High-Data-Rate DSL
IDSL Integrated Services Digital Network DSL
RDSL Rate-Adaptive DSL
SDSL Single-Line DSL +
Symmetric DSL
VDSL Very-High-Bit-Rate DSL
VADSL Very-High-Rate Asymmetric DSL
VDSL Very-High-Data-Rate DSL
DSL Domain Specific Language + Dynamic Simulation Language
DSLAM Digital Subscriber Line Access Multiplexer
D-SLR Digital Single Lens Reflex (camera)
DSM Distributed Shared Memory +
Domain-Specific Modeling
DSMA Digital Sense Multiple Access
DSML Directory Services Markup Language
DSN Data Source Name + Delivery Service Notification
DSO Dynamic Shared Object
DSOM Distributed System Object Model
DSP Delivery Service Partner +
Digital Signal Processing/Processor +
Digital Sound Processor +
Directory Synchronization Protocol [Lotus]
DSPT Display Station Pass-Thru [IBM]
DSQD Double Sided, Quad Density (diskette)
DSR Data Set Ready + Device Status Register +
Device Status Report
DSS Decision Support System + Digital Signature Standard +
Digital Spread Spectrum + Direct Station Selector
DSSA Domain Specific Software Architecture
DSSI Digital Standard Systems Interconnect [DEC]
DSSS Direct-Sequencing Spread Spectrum
DSSSL Document Style Semantics and Specifications Language
DSTN Double Supertwisted Nematic
DSU Data Service/Switching 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 Digital Terminal Adapter + Disk Transfer Area
.DTA Data (file name extension)
DTC Desktop Conferencing
DTCP Digital Transmission Copy Protection
[Hitachi, Intel, Panasonic, Sony, Toshiba]
DTD Document Type Definition
DTE Data Terminal Equipment + Dumb Terminal Emulator
DTF Distributed Test Facility
DTL Dialogue Tag Language [IBM] + Diode-Transistor Logic
DTM Digital Terrain Mapping
DTMF Data Tone Multiple Frequency + Dual Tone Multifrequency
DTP Desktop Publishing + Distributed Transaction Process
DTR Data Terminal Ready + Data Transfer Rate
DTS Digital Theatre Systems + Digital Transceiving System
Distributed Traffic Shaping [Cisco]
DTSS Dartmouth Time Sharing System
DTV Desktop Video + Digital Television
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 Digital Video
.DV DESQview Script (file name extension)
DVC Desktop Video Conferencing + Digital Video Camera +
Dual Voice Coil
DVD Digital Video Disk
DVD-A Digital Video Disk-Audio
DVD-AR Digital Video Disk-Audio Recording
DVD-R Digital Video Disk-Recordable
DVD-RAM Digital Versatile Disc-RAM
DVD-ROM Digital Versatile Disc-ROM
DVD-SR Digital Video Disk-Stream Recording
DVD-VR Digital Video Disk-Video Recording
DVE Digital Video Effect
DVI Digital Video Interactive + Digital Visual Interface
.DVI Device Independent (file name extension)
DVM Digital Volt Meter
DVMRP Distance Vector Multicast Routing Protocol [Internet]
DVOF Digital Video Over Fiber
DVR Digital Video/Voice Recorder
.DVR Device Driver (file name extension) (Also see .DRV)
DW Data Warehousing
DWDM Dense Wavelength Division Multiplexer
DWG Drawing
DWMT Discrete Wavelet Multitone
DWT Discrete Wavelet Transform
D2X Decimal To Hexadecimal [REXX]
.DXB Drawing Interchange Binary (file name extension)
[AutoCAD]
DXC Data Exchange Control
DXF Data Exchange File + Drawing Exchange Format
DXI Data Exchange Interface
DYNSLT Dynamic Select [IBM]
DYNSRC Dynamic Source

EA Effective Address + Extended Attribute [OS/2]
EAI Enterprise Application Integration
EAP Extensible Authentification Protocol
EAR Enterprise Archive + 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
EAX Environmental Audio Extensions [Creative]
EB Exabyte (1,024 petabytes)
(One Billion Billion characters of information)
EBASIC Extended BASIC
EBC EISA Bus Controller
EBCT Electron Beam Computed Tomography
EBCDIC Extended Binary Coded Decimal Interchange Code [IBM]
EBI Equivalent Background Input +
Extended Background Investigation
EBNF Extended Backus-Naur Form
EBOOK Electronic Book
EBPP Electric Bill Presentment and Payment
EBR Extended Boot Record
EBS Event-Based Sampling
EBT Electronic Benefits Transfer
EBXM Electronic Business XML
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
ECDL European Computer Driving Licence
ECHO European Commission Host Organization [Internet]
ECI External Call Interface
ECL Emitter Coupled Logic
ECM Electronic Control Module
ECMA European Computer Manufacturers Association
ECN Electronic Communications Network
ECNE Enterprise Certified NetWare Engineer [Novell]
ECP Enhanced/Extended Capabilities Port [Microsoft]
ECS Enhanced Chip Set
ECTL Electronic Communal Temporal Lobe
ECU EISA Configuration Utility
ED Erase Display
EDA Electronic Design Automation +
Embedded Document Architecture [Go Corporation]
EDB Embedded Database
EDC Electronic Digital Computer +
Enhanced Data Correction +
Error Detection and Correction
EDDC Extended Distance Data Cable
EDE Encrypt-Decrypt-Encrypt
EDG Electronic Program Guide
EDGAR Electronic Data Gathering, Analysis and Retrieval
EDGE Enhanced Data-Rates for Global Evolution
EDI Electronic Data Interchange +
Electronic Document Interchange [DEC]
EDIF Electronic Design Interchange Format
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 Enhanced/Eraseable/Extended Dynamic Random Access Memory
EDS Electronic Data Systems (corporation)
EDSAC * Electronic Delay Storage Automatic Calculator
EDTV Enhanced Definition Television
.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
EEDID Enhanced-Extended Display Identification Data
EEG Electroencephalogram
EEL Epsilon Extension Language
EEM Extended Memory Management
EEMAC Electrical & Electronic Manufacturers of Canada
EEMS Enhanced Expanded Memory Specification
EEPI Electronic Entertainment Policy Initiative
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 +
Extensible Firmware Interface
EFIGS English, French, Italian, German, Spanish
EFL Emitter Follower Logic
E-FORM Electronic Form
EFS Encrypting File System
EFTS Electronic Funds Transfer System
EGA Enhanced Graphics Adapter
EGP Exterior Gateway Protocol
EGREP Extended Global Regular Expression Print [Unix]
EHCI Enhanced Host Controller Interface
EHLLAPI Emulator High Level Language Application
Programming Interface [IBM]
EIA Electronic Industries Association
EICAS Engine Indicating and Crew Alerting System
EIDE Enhanced Integrated Drive Electronics
EIM Electronic Image Management
EIS Enterprise/Executive Information System
EISA Extended Industry Standard Architecture
EJB Enterprise JavaBeans
EL Electroluminescent (display) + Erase Line
ELAN Emulated Local Area Network
ELC Embedded Linking and Control
ELD Electronic License Distribution
ELEC Enterprise Local Exchange Carrier
ELF Executable and Linking Format +
Extremely Low Frequency
ELOS Embedded-Objects Linked Across Systems
ELPH Entr Level PowerShot [Canon]
ELS Entry Level System
EM Electronic Mail + Emphasized + End of Medium +
Expanded Memory
EMA Electronic Mail Association +
Enterprise Management/Memory 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
EMCC * Eckert-Mauchly Computer Company (World's first computer
company, founded by Presper Eckart and John Mauchly,
who invented and built the first UNIVAC)
EMF Extended Metafile Format [Microsoft]
EMI Electromagnetic Interference
.EML Electronic Mail (file name extension)
EMM Expanded Memory Manager
EMP Electro-Magnetic Pulse
EMR Electro-Magnetic Radiation +
Enhanced Metafile Record
EMS Electronic Mail System +
Electronic Message Service +
Energy Management System +
Enhanced Messaging Service +
Expanded Memory Specification [LIM]
EMSAPI Extended Messaging Services Application
Programming Interface
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] +
Electro-Optical System [Canon] +
End Of String + Error Correction Code on SIMM
EOSDIS Earth Observing System Data and Information System [NASA]
EOT Embedded Open Type (format) [Microsoft] +
End Of Table + End Of Tape (marker) + End Of Text +
End Of Transmission
EP Electrophotographic Engine
EPC Electronic Product Code
EPIC Explicitly Parallel Instruction Computing (chip) [Intel]
EPG Electronic Program Guide
EPL Effective Privilege Level
EPLD Electrically Programmable Logic Device
EPM Enhanced Editor for Presentation Manager [IBM] +
Enterprise Process Management [IBM]
EPP Enhanced Parallel Port
EPROCESS Executive Process
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 + Entity Relationship Diagram
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]
ERP Effective Radiated Power +
Enterprise Resource Planning
ERR Error
ER/RC Extended Result/Response Code
ERU Emergency Recovery Utility [Microsoft]
ES Extra Segment
ESA Enterprise Systems Architecture [IBM] +
European Space Agency
ESB Enterprise Service Bus
ESC EISA System Component + Escape
ESCD Extended System Configuration Data
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 + Emergency Startup Disk
ESDI Enhanced Small/System Device Interface
ESDRAM Enhanced SDRAM
ESF Extended Superframe
ESI End System Identifier +
Enhanced Serial Interface (specification) [Hayes]
ESMR Enhanced Specialized Mobile Radio
ESMTP Extended Simple Mail Transfer Protocol
ESN Electronic Security/Serial Number
ESP Emulation Sensing Processor +
Encapsulating Security Payload (header) +
Enhanced Serial Port [Hayes] + Enhanced Service Provider +
Enterprise System Platcorm + Estimated Selling Price +
Eudora Sharing Protocol [Qualcomm]
ESR Event Service Routine
ESS Electronic Switching System
ESSENCE Electronic Surveillance System for the Early Notification
of Community-Based Epidemics [Johns Hopkins University]
ESSID Extended Service Set Identifier
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]
E-TEXT Electronic Text
ETF Enriched Text Format
ETOM Electron-Trapping Optical Memory
ETPL Endorsed Tempest Products List
ETS Econometric Time Series
ETX End Of Text
EU Execution Unit
.EU European Union (Domain Name) [Internet]
EUC End-User Computing + Extended Unix Code [IBM]
EUDC End-User Defined Character
EUDORA (Named after author of story:
"Why I Live at the P.O.", Ms. Eudora Welty)
EUI End-User Interface
EULA End-User License Agreement
EUVL Extreme Ultraviolet Lithography
EVDO Evolution Data Only/Optimized
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]
EWTS Enterprise Web Training System
EXCA Exchangeable Card Architecture [Intel]
.EXE Executable (file name extension)
EXE2BIN Program used to convert an (.EXE) file to binary
format (.COM) file
EXIF Exchangeable Image File Format
EXM Enterprise Messaging Exchange [Lotus]
EXP Exponent
EXT External
EXTRN External Reference
E-ZINE Electronic Magazine

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)
FBC Find By Content
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
FCL Fibre Channel Loop
FCPGA Flip Chip Pin Grid Array [Intel]
FCR FIFO Control Register
FCRAM Fast-Cycle RAM
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
FDHD Floppy Drive High Density
FDIR Fault Detection, Isolation and Recovery
FDISK Fixed Disk
FDM Frequency Division Multiplexing
FDMA Frequency Division Multiple Access
FDSL (See DSL)
FDX Full Duplex
FEC Forward Error Correction
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
FFD Full Funtion Device
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]
FHS Fan Heat-Sink
FHSS Frequency-Hopping Spread Spectrum
FIA File Integrity Assessment
FIB Forwarding Information Base
FIF Fractal Image Format
FIFO First-In, First-Out
FILO First-In, Last-Out
FINDSTR Find Strings
FIOS (FiOS) Fiber Optic Services [Verizon]
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
FITS Flexible Image Transport System
FIU Fingerprint Identification Unit [Sony]
FIX Federal Internet Exchange
FK Foreign Key
FLA Four Letter Acronym
FLC Ferro-electric Liquid Crystal
FLD Field
FLIR Forward Looking Infrared (system)
FLL FoxPro Link Library [Microsoft Fox Pro]
FLOPS Floating Point Operations Per Second
.FLR Folder (file name extension)
FLV Flash Video
FM Frequency Modulation
FMD Fluorescent Multilayer Disk
FMRI Functional Magnetic Resonance Imaging
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
FOIP Fax Over Internet Protocol
FOIRL Fiber Optic Inter Repeater Link [IEEE]
FOLDOC Free On-Line Dictionary Of Computing
FOM Fiber Optics Modem
.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 Flexible Printed Circuit +
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
FPX FlashPix (format) [Kodak]
FQDN Fully Qualified Domain Name [Internet]
FRAD Frame Relay Access Device +
Frame Relay Assembler/Disassembler
FRAG Fragment + Fragmentation
FRAM Ferroelectric Random-Access Memory
FRC Functional Redundancy Checking
FRED Frame Editor + Front-End to Dish
FRMR Frame Reject
FRPI Flux Reversals Per Inch
FRS Family Radio Service
.FRS WordPerfect Graphics Driver (file name extension)
FS File Separator
FSB Front Side Bus
FSD File System Driver [OS/2]
FSE Full Screen Editor
FSF Free Software Foundation [Internet]
FSK Frequency Shift Keying
FSN Full Service Network
FSO Free Space Optics
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
FTTB Fiber To The Basement
FTTC Fiber To The Curb
FTTN Fiber To The Neighborhood
FTS Federal Telecommunication System
FTX Fault Tolerant Unix
FUI File Update Information
FUNC Function
FUS Fast User Switching
FUSE Far Ultraviolet Spectroscopic Explorer [JHUAPL]
FVT Full Video Translation
FWTK Firewall Toolkit
FXP File Exchange Protocol
FYI For Your Information

GA General Availability
GAAP Generally Accepted Accounting Principles
GAC Global Assembly Cache
GAL Generic Array Logic
GAMS General Algebraic Mathematical System
GAPI Gateway Application Programming Interface
GART Graphics Address Relocation Table
GATT Graphics Address Translation Table
GAWD Global Access Wireless Database
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]
GCCD Glass-Passivated Ceramic Chip Diode
GCR Group Code Recording
GDA Global Data Area + GNOME Data Access
GDB GNU Debugger
GDDM Graphics Data Display Manager
GDG Generation Data Group [IBM]
GDI Graphical Device Interface
GDLC Generic Data Link Control [IBM]
GDP Graphic Draw Primitive
GDR Gas Discharge Arrestor
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 Global Entity Ordering System +
GEOS Graphic Environment Operating System [Geoworks]
GET Get Execute Trigger
GFDL GNU Free Documentation License
GFI General Format Identifier + Ground-Fault Interceptor
GGP Gateway-Gateway Protocol [Internet]
GHZ Gigahertz
.GID Topics (file name extension) [Microsoft]
.GIF Graphics Interchange Format (file name extension)
GIG-E Gigabit Ethernet
GIGO Garbage In, Garbage Out
GII Global Information Infrastructure
GILS Government Information Locator Service
GIMP GNU Image Manipulation Program
GIMPS Great Internet Mersenne Prime Search
GINA Graphical Identification and Authentication
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]
GLL Geograpic Position-Latitude/Longitude
GLM General Linear Models
GLOBE Global Learning by Observations to Benefit
the Environment [Internet]
.GLY Glossary (file name extension) [Microsoft Word]
GMDI Gigabit Media-Dependent Interface
GML Generalized Markup Language
GMP Global Mobile Professional
GMR Giant Magneto-Resistive (read head technology)
GMRS General Mobile Radio Service
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)
GNOME GNU Network Object Model Environment
GOAD GNOME Object Activation Directory
GOS Grade Of Service
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
GPIO General Purpose Input/Output
GPL General Public License
GPR General Purpose Register [IBM]
GPRC Glass Passivated Rectifier Chip
GPRS General Packet Radio Service
GPS Global Positioning Satellite/System +
Global Product Specification
GPSS * General Purpose Systems Simulator (language)
GPU Graphics Processing Unit
GRADD Graphics Adapter Device Driver [IBM]
GRE Generic Routing Encapsulation + 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 + Global Service Provider
GSR Gigabit Switch Router
GSTN General Switched Telephone Network
GTE General Telephone Electronics (corporation)
GTF Generalized Timing Format
GTL Graphic Template Library +
Gunning Transceiver Logic
GTO Guide To Operations [IBM]
GTP * Geometry Theorem Prover
GTS Generic Traffic Shaping [Cisco]
GUI Graphical User Interface
GUID Globally Unique Identifier +
Global Universal Identifier
GVT Global Virtual Time
GW-BASIC Gee Whiz BASIC
GWES Graphic, Windowing and Event Subsystem
.gz Compressed file (compressed filename extension -
using GNU gzip compression/decompression program) [Unix]
GZIP GNU Zip

.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
HARP-MRI Harmonic Phase MRI
HASP Houston Automatic Spooling Priority (System)
HBA Host Bus Adapter
HCL Hardware Compatibility List
HCSS High Capacity Storage System
HCT Hardware Compatibility Test
HCU Home Computer User
HD Hard Disk + High Density
HDA Head Disk Assembly
HDC High Dependability Computing [Carnegie Mellon]
HDCD High Definition Compatible Digital
HDCP High-Bandwidth Digital Content Protection +
High Definition Copy Protection
HDD Hard Disk Drive
HDF Hierarchical Data Format [NCSA]
HDI Head to Disk Interference
HDL Hardware Description Language
HDLC High-Level Data Link Control
HDM Hardware Device Module
HDMI High-Definition Multimedia Interface
HDML Handheld Device Markup Language
HDR Header + High Data Rate +
High Dynamic Range (photography)
.HDR Header Data (file name extension)
HDSC High Density Signal Carrier [DEC]
HDSL (See DSL)
HDSS Holographic Data Storage System
HDT Host Digital Terminal
HDTV High Definition Television
HDVD High Definition Volumetric Display
HDW Hardware
HDX Half Duplex
HEOS High Earth Orbiting Satellite
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
HGP Human Genome Project
HH Hour
HID Human Interface Device
HIDS Host-Based Intrusion Detection System
HIF Hyper-G Interchange Format
HIFD High-Density Floppy Disk
HIL Human Interface Link [HP]
HIMEM High Memory
HIPPI High Performance Parallel Interface
HLA High Level Architecture
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
HMI Human-Machine Interface
HMM Hidden Markov Model
HMMP Hyper-Media Management Protocol
HMOS High Density Metal Oxide Semiconductor +
High Speed Metal Oxide Semiconductor
HMP Host Monitoring Protocol
HOL High Order Logic
HOLAP Hybrid OLAP
HOTT Hot Off The Tree (electronic newsletter)
HOV High Occupancy Vehicle
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
HPNA Home Phoneline Networking Alliance
HPOM Home Page Objects Model [Microsoft]
HPPA Hewlett-Packard Precision Architecture
HPPI High Performance Parallel Interface
HPR High Performance Routing [IBM]
HPSB High Performance Serial Bus
HPTL High Performance Technical Computing
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
HSDPA High Speed Download Packet Access
HSI Hue, Saturation, Intensity
HSM Hierarchical Storage Management
HSP High Speed Printer/Processor
HSSI High Speed Serial Interface
HST High Speed Technology [U.S. Robotics]
.HST History + Host (file name extensions)
HSV Hue Saturation Value
HTL Human In The Loop
HTML HyperText Markup Language
HTTP HyperText Transfer Protocol
HTTP-NG HTTP Next Generation
HTTPS HyperText Transfer Protocol Secure
HUD Heads Up Display
HUT Hopkins Ultraviolet Telescope
H/V Horizontal/Vertical
HVD Holographic Versatile Disc
HVP Horizontal & Vertical Position
H/W Hardware
HWCP Hardware Code Page
HWD Height-Width-Depth
HWDM Hyperfine Wave Division Multiplexing
.HYP Hyphenation (file name extension)
HYTELNET Hypertext-browser for Telnet Accessible Sites
Hz Hertz

IA Intel Architecture [Intel]
IAB Internet Architecture Board
IAC Inter-Application Communication [Macintosh]
IAD Integrated Access Device
IAEC International Address Element Code
IAFIS Integrated Automatic Fingerprint
Identification System
IAG Instruction Address Generation
IAK Internet Access Kit [IBM]
IAL * International Algorithmic Language
(ALGOL was first called IAL)
IANA Internet Assigned Numbers Authority
IAP Internet Access Provider
IAS Internet Access Server
IAT Import Address Table
IAUP Internet User Account Provider
IBC Instrument Bus Computer
IBCS Intel Binary Compatibility Specification
IBIP Information Based Indicia Program [U.S. Postal Service]
IBL Inbound Links [Google]
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
ICANN International Corporation for Assigned Names and Numbers
ICAP Internet Calendar Access Protocol [Lotus]
ICAS Intel Communicating Applications Specifications
ICB Internet Citizen's Band
ICCP Institute for the Certification of
Computing Professionals
ICD International Code Designator
ICE In-Circuit Emulator [Intel] +
Integrated Computing Environment [Langley Research] +
Internal Compiler Error
ICES Interference-Causing Equipment Standard
ICF Internet Connection Firewall [Microsoft]
ICI Image Component Information + Inter-CPU Interrupts
ICL Interface Clear
ICLID Incoming-Call Line Identification
ICM Image Color Matching [Kodak] + Incoming Message
.ICM Image Color Management (file name extension)
ICMP Internet Control Message Protocol [Novell]
.ICO Icon (file name extension)
ICOMP (iCOMP)Intel Comparative Microprocessor
Performance [Intel]
ICP Image Coprocessor + Integrated Channel Processor
ICQ I Seek You (messaging program0
ICR Intelligent Character Recognition
ICS Internet Connection Sharing [Microsoft] +
Intuitive Command Structure
ICSAPI Internet Connection Services API
ICU Instruction-Cache Unit +
Intel Configuration Utili