List of computing and IT abbreviations

0–9

• #!—Shebang
• /.—Slashdot
• 1GL—First-Generation Programming Language
• 1NF—First Normal Form
• 10B2—10BASE-2
• 10B5—10BASE-5
• 10B-F—10BASE-F
• 10B-FB—10BASE-FB
• 10B-FL—10BASE-FL
• 10B-FP—10BASE-FP
• 10B-T—10BASE-T
• 100B-FX—100BASE-FX
• 100B-T—100BASE-T
• 100B-TX—100BASE-TX
• 100BVG—100BASE-VG
• 286—Intel 80286 processor
• 2B1Q—2 Binary 1 Quaternary
• 2FA—Two-factor authentication
• 2GL—Second-Generation Programming Language
• 2NF—Second Normal Form
• 3GL—Third-Generation Programming Language
• 3GPP—3rd Generation Partnership Project—'3G comms
• 3GPP2—3rd Generation Partnership Project 2
• 3NF—Third Normal Form
• 386—Intel 80386 processor
• 486—Intel 80486 processor
• 4B5BLF—4 Byte 5 Byte Local Fiber
• 4GL—Fourth-Generation Programming Language
• 4NF—Fourth Normal Form
• 5GL—Fifth-Generation Programming Language
• 5NF—Fifth Normal Form
• 6NF—Sixth Normal Form
• 8B10BLF—8 Byte 10 Byte Local Fiber
• 802.11—Wireless LAN

  A

• AAA—Authentication Authorization, Accounting
• AABB—Axis Aligned Bounding Box
• AAC—Advanced Audio Coding
• AAL—ATM Adaptation Layer
• AALC—ATM Adaptation Layer Connection
• AARP—AppleTalk Address Resolution Protocol
• ABAC—Attribute-Based Access Control
• ABCL—Actor-Based Concurrent Language
• ABI—Application Binary Interface
• ABM—Asynchronous Balanced Mode
• ABR—Area Border Router
• ABR—Auto Baud-Rate detection
• ABR—Available Bitrate
• ABR—Average Bitrate
• AC—Acoustic Coupler
• AC—Alternating Current
• ACD—Automatic Call Distributor
• ACE—Advanced Computing Environment
• ACID—Atomicity Consistency Isolation Durability
• ACK—ACKnowledgement
• ACK—Amsterdam Compiler Kit
• ACL—Access Control List
• ACL—Active Current Loop
• ACM—Association for Computing Machinery
• ACME—Automated Classification of Medical Entities
• ACP—Airline Control Program
• ACPI—Advanced Configuration and Power Interface
• ACR—Allowed Cell Rate
• ACR—Attenuation to Crosstalk Ratio
• AD—Active Directory
• AD—Administrative Domain
• ADC—Analog-to-Digital Converter
• ADC—Apple Display Connector
• ADB—Apple Desktop Bus
• ADCCP—Advanced Data Communications Control Procedures
• ADO—ActiveX Data Objects
• ADSL—Asymmetric Digital Subscriber Line
• ADT—Abstract Data Type
• AE—Adaptive Equalizer
• AES—Advanced Encryption Standard
• AF—Anisotropic Filtering
• AFP—Apple Filing Protocol
• AGP—Accelerated Graphics Port
• AH—Active Hub
• AI—Artificial Intelligence
• AIX—Advanced Interactive eXecutive
• Ajax—Asynchronous JavaScript and XML
• AL—Active Link
• AL—Access List
• ALAC—Apple Lossless Audio Codec
• ALGOL—Algorithmic Language
• ALSA—Advanced Linux Sound Architecture
• ALU—Arithmetic and Logical Unit
• AM—Access Method
• AM—Active Matrix
• AMOLED—Active-Matrix Organic Light-Emitting Diode
• AM—Active Monitor
• AM—Allied Mastercomputer
• AM—Amplitude Modulation
• AMD—Advanced Micro Devices
• AMQP—Advanced Message Queuing Protocol
• AMR—Audio Modem Riser
• ANN—Artificial Neural Network
• ANSI—American National Standards Institute
• ANT—Another Neat Tool
• AoE—ATA over Ethernet
• AOP—Aspect-Oriented Programming
• APCI—Application-Layer Protocol Control Information
• API—Application Programming Interface
• APIC—Advanced Programmable Interrupt Controller
• APIPA—Automatic Private IP Addressing
• APL—A Programming Language
• APR—Apache Portable Runtime
• ARC—Adaptive Replacement Cache
• ARC—Advanced RISC Computing
• ARIN—American Registry for Internet Numbers
• ARM—Advanced RISC Machines
• AROS—AROS Research Operating System
• ARP—Address Resolution Protocol
• ARPA—Address and Routing Parameter Area
• ARPA—Advanced Research Projects Agency
• ARPANET—Advanced Research Projects Agency Network
• AS—Access Server
• ASCII—American Standard Code for Information Interchange
• AuthIP—Authenticated Internet Protocol
• ASET—Automated Security Enhancement Tool
• ASG—Abstract Semantic Graph
• ASIC—Application-Specific Integrated Circuit
• ASIMO—Advanced Step in Innovative Mobility
• ASLR—Address Space Layout Randomization
• ASM—Algorithmic State Machine
• ASMP—Asymmetric Multiprocessing
• ASN.1—Abstract Syntax Notation 1
• ASP—Active Server Pages
• ASP—Application Service Provider
• ASR—Asynchronous Signal Routine
• AST—Abstract Syntax Tree
• AT—Advanced Technology
• AT—Access Time
• AT—Active Terminator
• ATA—Advanced Technology Attachment
• ATAG—Authoring Tool Accessibility Guidelines
• ATAPI—Advanced Technology Attachment Packet Interface
• ATM—Asynchronous Transfer Mode
• AuthN—Authentication
• AuthZ—Authorization
• AV—Antivirus
• AVC—Advanced Video Coding
• AVI—Audio Video Interleaved
• AWK—Aho Weinberger Kernighan
• AWS-Amazon Web Services
• AWT—Abstract Window Toolkit
• AWFL—Acronym With Four Letters

  B

• B2B—Business-to-Business
• B2C—Business-to-Consumer
• B2E—Business-to-Employee
• BAL—Basic Assembly Language
• BAM—Block Availability Map
• Bash—Bourne-again shell
• BASIC—Beginner's All-Purpose Symbolic Instruction Code
• BBP—Baseband Processor
• BBS—Bulletin Board System
• BC—Business Continuity
• BCD—Binary Coded Decimal
• BCD—Boot Configuration Data
• BCNF—Boyce–Codd normal form
• BCP-Business Continuity Planning
• BEEP—Blocks Extensible Exchange Protocol
• BER—Bit Error Rate
• BFD—Bidirectional Forwarding Detection
• BFD—Binary File Descriptor
• BFS—Breadth-First Search
• BFT—Byzantine Fault Tolerant
• BGP—Border Gateway Protocol
• BI—Business Intelligence
• BiDi—Bi-Directional
• bin—binary
• BINAC—Binary Automatic Computer
• BIND—Berkeley Internet Name Domain
• BIOS—Basic Input Output System
• BJT—Bipolar Junction Transistor
• bit—binary digit
• Blob—Binary large object
• Blog—Web Log
• BMP—Basic Multilingual Plane
• BNC—Baby Neill Constant
• BOINC—Berkeley Open Infrastructure for Network Computing
• BOM—Byte Order Mark
• BOOTP—Bootstrap Protocol
• BPDU—Bridge Protocol Data Unit
• BPEL—Business Process Execution Language
• BPL—Broadband over Power Lines
• BPM—Business Process Management
• BPM—Business Process Modeling
• bps—bits per second
• BRM—Business Reference Model
• BRMS—Business Rule Management System
• BRR—Business Readiness Rating
• BRS—Broadband Radio Service
• BSA—Business Software Alliance
• BSB—Backside Bus
• BSD—Berkeley Software Distribution
• BSoD—Blue Screen of Death
• BSS—Block Started by Symbol
• BT—BitTorrent
• BT—Bluetooth
• B TAM—Basic Telecommunications Access Method
• BW—Bandwidth
• BYOD—Bring Your Own Device
• Byte—By eight

  C

• CA—Computer Accountancy
• CAD—Computer-Aided Design
• CAE—Computer-Aided Engineering
• CAID—Computer-Aided Industrial Design
• CAI—Computer-Aided Instruction
• CAM—Computer-Aided Manufacturing
• CAP—Consistency Availability Partition tolerance
• CAPTCHA—Completely Automated Public Turing Test to tell Computers and Humans Apart
• CAT—Computer-Aided Translation
• CAQ—Computer-Aided Quality Assurance
• CASE—Computer-Aided Software Engineering
• cc—C Compiler
• CD—Compact Disc
• CDE—Common Desktop Environment
• CDFS—Compact Disk File System
• CDMA—Code Division Multiple Access
• CDN—Content Delivery Network
• CDP—Cisco Discovery Protocol
• CDP—Continuous Data Protection
• CD-R—CD-Recordable
• CD-ROM—CD Read-Only Memory
• CD-RW—CD-Rewritable
• CDSA—Common Data Security Architecture
• CERT—Computer Emergency Response Team
• CES—Consumer Electronics Show
• CF—Compact Flash
• CFD—Computational Fluid Dynamics
• CFG—Context-Free Grammar
• CFG—Control Flow Graph
• CG—Computer Graphics
• CGA—Color Graphics Array
• CGI—Common Gateway Interface
• CGI—Computer-Generated Imagery
• CGT—Computational Graph Theory
• CHAP—Challenge-Handshake Authentication Protocol
• CHS—Cylinder-Head-Sector
• CIDR—Classless Inter-Domain Routing
• CIFS—Common Internet Filesystem
• CIM—Common Information Model
• CIM—Computationally Independent Model
• CIO—Chief Information Officer
• CIR—Committed information rate
• CISC—Complex Instruction Set Computer
• CJK—Chinese, Japanese, and Korean
• CJKV—Chinese, Japanese, Korean, and Vietnamese
• CLI—Command Line Interface
• CLR—Common Language Runtime
• CM—Configuration Management
• CM—Content Management
• CMDB—Configuration Management Database
• CMMI—Capability Maturity Model Integration
• CMOS—Complementary Metal-Oxide Semiconductor
• CMO—Current Mode of Operation
• CMS—Content Management System
• CN—Canonical Name
• CN—Common Name
• CNC—Computer Numerical Control
• CNG—Cryptographic Next Generation
• CNG—Cryptography Next Generation
• CNR—Communications and Networking Riser
• COBOL—Common Business-Oriented Language
• COM—Component Object Model or communication
• CORBA—Common Object Request Broker Architecture
• CORS—Cross-Origin Resource Sharing
• COTS—Commercial Off-The-Shelf
• CPA—Cell Processor Architecture
• CPAN—Comprehensive Perl Archive Network
• CP/M—Control Program/Monitor
• CPRI—Common Public Radio Interface
• CPS—characters per second
• CPU—Central Processing Unit
• CR—Carriage Return
• CRAN—Comprehensive R Archive Network
• CRC—Cyclic Redundancy Check
• CRLF—Carriage Return Line Feeds
• CRM—Customer Relationship Management
• CRS—Computer Reservations System
• CRT—Cathode Ray Tube
• CRUD—Create, Read, Update and Delete
• CS—Cable Select
• CS—Computer Science
• CSE—Computer Science and Engineering
• CSI—Common System Interface
• CSM—Compatibility Support Module
• CSMA/CD—Carrier sense multiple access with collision detection
• CSP—Cloud Service Provider
• CSP—Communicating Sequential Processes
• CSRF—Cross-Site Request Forgery
• CSS—Cascading Style Sheets
• CSS—Content-Scrambling System
• CSS—Closed Source Software
• CSS—Cross-Site Scripting
• CSV—Comma-Separated Values
• CT—Computerized Tomography
• CTAN—Comprehensive TeX Archive Network
• CTCP—Client-To-Client Protocol
• CTI—Computer Telephony Integration
• CTFE—Compile Time Function Execution
• CTL—Computational Tree Logic
• CTM—Close To Metal
• CTS—Clear To Send
• CTSS—Compatible Time-Sharing System
• CUA—Common User Access
• Concurrent Versions System—Concurrent Versioning System|CVS
• CVS—Concurrent Versioning System
• CX—Customer Experience

  D

• DAC—Digital-To-Analog Converter
• DAC—Discretionary Access Control
• DAL—Database Abstraction Layer
• DAO—Data Access Object
• DAO—Data Access Objects
• DAO—Disk-At-Once
• DAP—Directory Access Protocol
• DAR-Direct Access Recovery
• DARPA—Defense Advanced Research Projects Agency
• DAS- Direct Attached Storage
• DAT—Digital Audio Tape
• DB—Database
• DSKT-Desktop
• DBA—Database Administrator
• DBCS—Double Byte Character Set
• DBMS—Database Management System
• DCC—Direct Client-to-Client
• DCCP—Datagram Congestion Control Protocol
• DCCA—Debian Common Core Alliance
• DCL—Data Control Language
• DCS—Distributed Control System
• DCMI—Dublin Core Metadata Initiative
• DCOM—Distributed Component Object Model
• DD—Double Density
• DDE—Dynamic Data Exchange
• DDI—DNS DHCP & IP Address management
• DDL—Data Definition Language
• DDoS—Distributed Denial of Service
• DDR—Double Data Rate
• DEC—Digital Equipment Corporation
• DES—Data Encryption Standard
• :/dev|dev—development
• DFA—Deterministic Finite Automaton
• DFD—Data Flow Diagram
• DFS—Depth-First Search
• DFS—Distributed File System
• DGD—Dworkin's Game Driver
• DHCP—Dynamic Host Configuration Protocol
• DHTML—Dynamic Hypertext Markup Language
• DIF—Data Integrity Field
• DIMM—Dual Inline Memory Module
• DIN—Deutsches Institut für Normung
• DIP—Dual In-line Package
• DISM—Deployment Image and Service Management Tool
• DIVX—Digital Video Express
• DKIM—Domain Keys Identified Mail
• DL—Download
• DLL—Dynamic Link Library
• DLNA—Digital Living Network Alliance
• DLP—Data loss protection
• DMA—Direct Memory Access
• DMCA—Digital Millennium Copyright Act
• DMI—Direct Media Interface
• DML—Data Manipulation Language
• DML—Definitive Media Library
• DMR—Dennis M. Ritchie
• DMZ—Demilitarized Zone
• DN—Distinguished Name
• DND—Drag-and-Drop
• DNS—Domain Name System
• DOA—Dead on Arrival
• DOCSIS—Data Over Cable Service Interface Specification
• DOM—Document Object Model
• DoS—Denial of Service
• DOS—Disk Operating System
• DP—Dot Pitch
• DPC—Deferred Procedure Call
• DPI—Deep Packet Inspection
• DPI—Dots Per Inch
• DPMI—DOS Protected Mode Interface
• DPMS—Display Power Management Signaling
• DR—Disaster Recovery
• DRAM—Dynamic Random-Access Memory
• DR-DOS—Digital Research - Disk Operating System
• DRI—Direct Rendering Infrastructure
• DRM—Digital Rights Management
• DRM—Direct Rendering Manager
• DSA—Digital Signature Algorithm
• DSDL—Document Schema Definition Languages
• DSDM—Dynamic Systems Development Method
• DSL—Digital Subscriber Line
• DSL—Domain-Specific Language
• DSLAM—Digital Subscriber Line Access Multiplexer
• DSN—Database Source Name
• DSN—Data Set Name
• DSP—Digital Signal Processor
• DSSSL—Document Style Semantics and Specification Language
• DTD—Document Type Definition
• DTE—Data Terminal Equipment or data transfer rate
• DTP—Desktop Publishing
• DTR—Data Terminal Ready or Data transfer rate
• DVD—Digital Versatile Disc
• DVD-R—DVD-Recordable
• DVD-ROM—DVD-Read Only Memory
• DVD-RW—DVD-Rewritable
• DVI—Digital Visual Interface
• DVR—Digital Video Recorder
• DW—Data Warehouse

  E

• EAI—Enterprise Application Integration
• EAP—Extensible Authentication Protocol
• EAS—Exchange ActiveSync
• EBCDIC—Extended Binary Coded Decimal Interchange Code
• EBML—Extensible Binary Meta Language
• ECC—Elliptic Curve Cryptography
• ECMA—European Computer Manufacturers Association
• ECN—Explicit Congestion Notification
• ECOS—Embedded Configurable Operating System
• ECRS—Expense and Cost Recovery System
• EDA—Electronic Design Automation
• EDGE— Enhanced Data rates for GSM Evolution
• EDI—Electronic Data Interchange
• EDO—Extended Data Out
• EDSAC—Electronic Delay Storage Automatic Calculator
• EDVAC—Electronic Discrete Variable Automatic Computer
• EEPROM—Electronically Erasable Programmable Read-Only Memory
• EFF—Electronic Frontier Foundation
• EFI—Extensible Firmware Interface
• EFM—Eight-to-Fourteen Modulation
• EFM—Ethernet in the First Mile
• EFS—Encrypting File System
• EGA—Enhanced Graphics Array
• E-mail—Electronic mail
• EGP—Exterior Gateway Protocol
• eID—electronic ID card
• EIDE—Enhanced IDE
• EIGRP—Enhanced Interior Gateway Routing Protocol
• EISA—Extended Industry Standard Architecture
• ELF—Extremely Low Frequency
• ELF—Executable and Linkable Format
• ELM—ELectronic Mail
• EMACS—Editor MACroS
• EMS—Expanded Memory Specification
• ENIAC—Electronic Numerical Integrator And Computer
• EOD—End of Day
• EOF—End of File
• EOL—End of Line
• EOM—End Of Message
• EOS—End OF Support
• EPIC—Explicitly Parallel Instruction Computing
• EPROM—Erasable Programmable Read-Only Memory
• ERD—Entity-Relationship Diagram
• ERM—Entity-Relationship Model
• ERP—Enterprise Resource Planning
• eSATA—external SATA
• ESB—Enterprise service bus
• ESCON—Enterprise Systems Connection
• ESD—Electrostatic Discharge
• ESI—Electronically Stored Information
• ESR—Eric Steven Raymond
• ETL—Extract, Transform, Load
• ETW—Event Tracing for Windows
• EUC—Extended Unix Code
• EULA—End User License Agreement
• EWM—Enterprise Work Management
• EWMH—Extended Window Manager Hints
• EXT—EXTended file system
• ETA—Estimated Time of Arrival

  F

• FAP—FORTRAN Assembly Program
• FASM—Flat ASseMbler
• FAT—File Allocation Table
• FAQ—Frequently Asked Questions
• FBDIMM—Fully Buffered Dual Inline Memory Module
• FC-AL—Fibre Channel Arbitrated Loop
• FCB—File Control Block
• FCS—Frame Check Sequence
• FDC—Floppy Disk Controller
• FDS—Fedora Directory Server
• FDD—Frequency-Division Duplexing
• FDD—Floppy Disk Drive
• FDDI—Fiber Distributed Data Interface
• FDM—Frequency-Division Multiplexing
• FDMA—Frequency-Division Multiple Access
• FEC—Forward Error Correction
• FEMB—Front-End Motherboard
• FET—Field Effect Transistor
• FHS—Filesystem Hierarchy Standard
• FICON—FIber CONnectivity
• FIFO—First In First Out
• FIPS—Federal Information Processing Standards
• FL—Function Level
• FLAC—Free Lossless Audio Codec
• FLOPS—FLoating-Point Operations Per Second
• FLOSS—Free/Libre/Open Source Software
• FMC— Fixed Mobile Convergence "Mobile UC or Unified Communications over Wireless"
• FMO—Future Mode of Operation
• FOLDOC—Free On-line Dictionary of Computing
• FOSDEM—Free and Open source Software Developers' European Meeting
• FOSI—Formatted Output Specification Instance
• FOSS—Free and Open Source Software
• FP—Function Programming
• FPGA—Field Programmable Gate Array
• FPS—Floating Point Systems
• FPU—Floating Point Unit
• FRU—Field Replaceable Unit
• FS—File System
• FSB—Front Side Bus
• fsck—File System Check
• FSF—Free Software Foundation
• FSM—Finite State Machine
• FTTA—Fiber To The Antenna
• FTTC—Fiber To The Curb
• FTTH—Fiber To The Home
• FTTP—Fiber To The Premises
• FTP—File Transfer Protocol
• FQDN—Fully Qualified Domain Name
• FUD—Fear Uncertainty Doubt
• FWS—Folding White Space
• FXP—File eXchange Protocol
• FYI—For Your Information
• FVEK—Full Volume Encryption Key

  G

• G11N—Globalization
• Gas—GNU Assembler
• Gb—Gigabit
• GB—Gigabyte
• GCC—GNU Compiler Collection
• GCJ—GNU Compiler for Java
• GCP-Google Cloud Platform
• GCR—Group Coded Recording
• GDB—GNU Debugger
• GDI—Graphics Device Interface
• GFDL—GNU Free Documentation License
• GIF—Graphics Interchange Format
• GIGO—Garbage In, Garbage Out
• GIMP—GNU Image Manipulation Program
• GIMPS—Great Internet Mersenne Prime Search
• GIS—Geographic Information System
• GLUT—OpenGL Utility Toolkit
• GML—Geography Markup Language
• GNOME—GNU Network Object Model Environment
• GNU—GNU's Not Unix
• GOMS—Goals, Operators, Methods, and Selection rules
• GPASM—GNU PIC ASseMbler
• GPFS—General Parallel File System
• GPG—GNU Privacy Guard
• GPGPU—General-Purpose Computing on Graphics Processing Units
• GPIB—General-Purpose Instrumentation Bus
• GPL—General Public License
• GPL—General-Purpose Language
• GPRS—General Packet Radio Service
• GPT—GUID Partition Table
• GPU—Graphics Processing Unit
• GRUB—Grand Unified Boot-Loader
• GERAN—GSM EDGE Radio Access Network
• GSM—Global System for Mobile Communications
• GTK+—GIMP Toolkit
• GUI—Graphical User Interface
• GUID—Globally Unique IDentifier
• GWT—Google Web Toolkit
• GYR—IT Networking

  H

• HA—High Availability
• HAL—Hardware Abstraction Layer
• HARD—HTML Application Rapid Development
• HASP—Houston Automatic Spooling Priority
• HBA—Host Bus Adapter
• HCI—Human Computer Interaction
• HD—High Density
• HDD—Hard Disk Drive
• HCL—Hardware Compatibility List
• HD DVD—High Definition DVD
• HDL—Hardware Description Language
• HDMI—High-Definition Multimedia Interface
• HECI—Host Embedded Controller Interface
• HF—High Frequency
• HFS—Hierarchical File System
• HHD—Hybrid Hard Drive
• HID—Human Interface Device
• HIG—Human Interface Guidelines
• HIRD—Hurd of Interfaces Representing Depth
• HLASM—High Level ASseMbler
• HLS—HTTP Live Streaming
• HMA—High Memory Area
• HP—Hewlett-Packard
• HPC—High-Performance Computing
• HPFS—High Performance File System
• HSDPA—High-Speed Downlink Packet Access
• HTC—High-Throughput Computing
• HSM—Hierarchical Storage Management
• HT—Hyper Threading
• HTM—Hierarchical Temporal Memory
• HTML—Hypertext Markup Language
• HTTP—Hypertext Transfer Protocol
• HTTPd—Hypertext Transport Protocol Daemon
• HTTPS—HTTP Secure
• HTX—HyperTransport eXpansion
• HURD—Hird of Unix-Replacing Daemons
• HVD—Holographic Versatile Disc
• Hz—Hertz

  I

• I²C—Inter-Integrated Circuit
• I²S—Integrated Interchip Sound
• I18N—Internationalization
• IANA—Internet Assigned Numbers Authority
• IaaS—Infrastructure as a Service
• iBCS—Intel Binary Compatibility Standard
• IBM—International Business Machines
• IC—Integrated Circuit
• ICANN—Internet Corporation for Assigned Names and Numbers
• ICE—In-Circuit Emulator
• ICE—Intrusion Countermeasure Electronics
• ICH—I/O Controller Hub
• ICMP—Internet Control Message Protocol
• ICP—Internet Cache Protocol
• ICS—Internet Connection Sharing
• ICT—Information and Communication Technology
• IDE—Integrated Development Environment
• IDE—Integrated Drive Electronics
• IDF—Intermediate Distribution Frame
• IDF—Intermediate Data Format
• IDL—Interactive Data Language
• IDL—Interface Definition Language
• IDS—Intrusion Detection System
• IE—Internet Explorer
• IEC—International Electrotechnical Commission
• IEEE—Institute of Electrical and Electronics Engineers
• IETF—Internet Engineering Task Force
• IFGICT—International Federation of Global & Green ICT
• IFL—Integrated Facility for Linux
• IGMP—Internet Group Management Protocol
• IGRP—Interior Gateway Routing Protocol
• IHV—Independent Hardware Vendor
• IIOP—Internet Inter-Orb Protocol
• IIS—Internet Information Services
• IKE—Internet Key Exchange
• IL—Intermediate Language
• IM—Instant Messaging
• IMAP—Internet Message Access Protocol
• IME—Input Method Editor
• IMR—Internet Monthly Report
• INFOSEC—Information Systems Security
• I/O—Input/output
• IoT—Internet of Things
• IP—Intellectual Property
• IP—Internet Protocol
• IPAM—IP Address Management
• IPC—Inter-Process Communication
• IPL—Initial Program Load
• IPMI—Intelligent Platform Management Interface
• IPO—Inter Procedural Optimization
• IPP—Internet Printing Protocol
• IPS—In-Plane Switching
• IPS—Instructions Per Second
• IPS—Intrusion Prevention System
• IPsec—Internet Protocol security
• IPTV—Internet Protocol Television
• IPv4—Internet Protocol version 4
• IPv6—Internet Protocol version 6
• IPX—Internetwork Packet Exchange
• IR—Intermediate Representation
• IRC—Internet Relay Chat
• IrDA—Infrared Data Association
• IRI—Internationalized Resource Identifier
• IRP—I/O Request Packet
• IRQ—Interrupt Request
• IS—Information Systems
• IS-IS—Intermediate System to Intermediate System
• ISA—Industry Standard Architecture
• ISA—Instruction Set Architecture
• ISAM—Indexed Sequential Access Method
• ISATAP—Intra-Site Automatic Tunnel Addressing Protocol
• ISC—Internet Storm Center
• iSCSI—Internet Small Computer System Interface
• ISDN—Integrated Services Digital Network
• ISO—International Organization for Standardization
• iSNS—Internet Storage Name Service
• ISP—Internet Service Provider
• ISPF—Interactive System Productivity Facility
• ISR—Interrupt Service Routine
• ISV—Independent Software Vendor
• IT—Information Technology
• ITIL—Information Technology Infrastructure Library
• ITL—Interval Temporal Logic
• ITU—International Telecommunication Union
• IVRS—Interactive Voice Response System
• IVCR—Interactive Virtual Classroom
• ISDN—Integrated service digital network

  J

• J2EE—Java 2 Enterprise Edition
• J2ME—Java 2 Micro Edition
• J2SE—Java 2 Standard Edition
• JAXB—Java Architecture for XML Binding
• JAX-RPC—Java XML for Remote Procedure Calls
• JAXP—Java API for XML Processing
• JBOD—Just a Bunch of Disks
• JCE Java Cryptography Extension
• JCL—Job Control Language
• JCP—Java Community Process
• JDBC—Java Database Connectivity
• JDK—Java Development Kit
• JEE—Java Enterprise Edition
• JES—Job Entry Subsystem
• JDS—Java Desktop System
• JFC—Java Foundation Classes
• JFET—Junction Field-Effect Transistor
• JFS—IBM Journaling File System
• JINI—Jini Is Not Initials
• JIT—Just-In-Time
• JME—Java Micro Edition
• JMX—Java Management Extensions
• JMS—Java Message Service
• JNDI—Java Naming and Directory Interface
• JNI—Java Native Interface
• JNZ—Jump non-zero
• JPEG—Joint Photographic Experts Group
• JRE—Java Runtime Environment
• JS—JavaScript
• JSE—Java Standard Edition
• JSON—JavaScript Object Notation
• JSP—Jackson Structured Programming
• JSP—JavaServer Pages
• JTAG—Joint Test Action Group
• JVM—Java Virtual Machine

  K

• K&R—Kernighan and Ritchie
• KB—Keyboard
• Kb—Kilobit
• KB—Kilobyte
• KB—Knowledge Base
• KiB—Kibibyte
• KDE—K Desktop Environment
• kHz—Kilohertz
• KM—Knowledge Machine
• KRL—Knowledge Representation Language
• KVM—Keyboard, Video, Mouse

  L

• L10N—Localization
• L2TP—Layer two Tunneling Protocol
• LACP—Link Aggregation Control Protocol
• LAMP—Linux Apache MySQL Perl
• LAMP—Linux Apache MySQL PHP
• LAMP—Linux Apache MySQL Python
• LAN—Local Area Network
• LBA—Logical Block Addressing
• LB—Load Balancer
• LCD—Liquid Crystal Display
• LCR—Least Cost Routing
• LCOS—Liquid Crystal On Silicon
• LDAP—Lightweight Directory Access Protocol
• LE—Logical Extents
• LED—Light-Emitting Diode
• LF—Line Feed
• LF—Low Frequency
• LFS—Linux From Scratch
• LGPL—Lesser General Public License
• LIB—LIBrary
• LIF—Low Insertion Force
• LIFO—Last In First Out
• LILO—Linux Loader
• LIP—Loop Initialization Primitive
• LISP—LISt Processing
• LKML—Linux Kernel Mailing List
• LM—Lan Manager
• LOC—Lines of Code
• LPC—Lars Pensjö C
• LPI—Linux Professional Institute
• LPT Line Print Terminal
• LRU—Least Recently Used
• LSB—Least Significant Bit
• LSB—Linux Standard Base
• LSI—Large-Scale Integration
• LTE—Long Term Evolution
• LTL—Linear Temporal Logic
• LTR—Left-to-Right
• LUG—Linux User Group
• LUN—Logical Unit Number
• LV—Logical Volume
• LVD—Low Voltage Differential
• LVM—Logical Volume Management
• LZW—Lempel-Ziv-Welch
• LGA—Land Grid Array

  M

• MAC—Mandatory Access
• MAC—Media Access Control
• MANET—Mobile Ad-Hoc Network
• MAN—Metropolitan Area Network
• MAPI—Messaging Application Programming Interface
• MBCS—Multi Byte Character Set
• MBD—Model-Based Design
• MBR—Master Boot Record
• Mb—Megabit
• MB—Megabyte
• MCAD—Microsoft Certified Application Developer
• MCAS—Microsoft Certified Application Specialist
• MCA—Micro Channel Architecture
• MCA—Microsoft Certified Architect
• MCDBA—Microsoft Certified DataBase Administrator
• MCDST—Microsoft Certified Desktop Support Technician
• MCITP—Microsoft Certified Information Technology Professional
• MCM—Microsoft Certified Master
• MCPC—Multiple Channels Per Carrier
• MCPD—Microsoft Certified Professional Developer
• MCP—Microsoft Certified Professional
• MCSA—Microsoft Certified Systems Administrator
• MCSD—Microsoft Certified Solution Developer
• MCSE—Microsoft Certified Systems Engineer
• MCTS—Microsoft Certified Technology Specialist
• MCT—Microsoft Certified Trainer
• MDA—Monochrome Display Adapter
• MDA—Mail Delivery Agent
• MDA—Model-Driven Architecture
• MDD/MDSD—Model-Driven Development
• MDF—Main Distribution Frame
• MDI—Multiple Document Interface
• MDM-Master Data Management
• ME—Microsoft Edge
• ME— Millennium Edition
• MFC—Microsoft Foundation Classes
• MFM—Modified Frequency Modulation
• MF—Medium Frequency
• MGCP—Media Gateway Control Protocol
• MHz—Megahertz
• MIB—Management Information Base
• MICR—Magnetic Ink Character Recognition
• MIDI—Musical Instrument Digital Interface
• MIMD—Multiple Instruction, Multiple Data
• MIME—Multipurpose Internet Mail Extensions
• MIMO—Multiple-Input Multiple-Output
• MINIX—MIni-uNIX
• MIPS—Microprocessor without Interlocked Pipeline Stages
• MIPS—Million Instructions Per Second
• MISD—Multiple Instruction, Single Data
• MIS—Management Information Systems
• MIT—Massachusetts Institute of Technology
• ML-Machine Learning
• MMC— Microsoft Management Console
• MMDS—Mortality Medical Data System
• MMDS—Multichannel Multipoint Distribution Service
• MMF—Multi-Mode Fiber
• MMIO—Memory-Mapped I/O
• MMI—Man Machine Interface.
• MMORPG—Massively Multiplayer Online Role-Playing Game
• MMU—Memory Management Unit
• MMX—Multi-Media Extensions
• MNG—Multiple-image Network Graphics
• MoBo—Motherboard
• MOM—Message-Oriented Middleware
• MOO—MUD Object Oriented
• MOP—Meta-Object Protocol
• MOSFET—Metal-Oxide Semiconductor Field Effect Transistor
• MOS—Microsoft Office Specialist
• MOTD—Message Of The Day
• MOUS—Microsoft Office User Specialist
• MOV—Apple QuickTime Multimedia File
• MPAA—Motion Picture Association of America
• MPEG—Motion Pictures Experts Group
• MPLS—Multiprotocol Label Switching
• MPL—Mozilla Public License
• MPU—Microprocessor Unit
• MS-DOS—Microsoft DOS
• MSA—Mail Submission Agent
• MSB—Most Significant Bit
• MSDN—Microsoft Developer Network
• MSI—Medium-Scale Integration
• MSI—Message Signaled Interrupt
• MSI—Microsoft Installer
• MSN—Microsoft Network
• MS—Microsoft
• MS—Memory Stick
• MTA—Mail Transfer Agent
• MTA—Microsoft Technology Associate
• MTBF—Mean Time Between Failures
• MTU—Maximum Transmission Unit
• MT—Machine Translation
• MUA—Mail User Agent
• MUD—Multi-User Dungeon
• MU-Memory Unit
• MVC—Model-View-Controller
• MVP—Most Valuable Professional
• MVS—Multiple Virtual Storage
• MWC—Mobile World Congress
• MXF—Material Exchange Format
• MX—Mail exchange

  N

• NAC—Network Access Control
• NACK—Negative ACKnowledgement
• NAK—Negative AcKnowledge Character
• NaN—Not a Number
• NAP—Network Access Protection
• NAS—Network-Attached Storage
• NASM—Netwide ASseMbler
• NAT—Network Address Translation
• NCP—NetWare Core Protocol
• NCQ—Native Command Queuing
• NCSA—National Center for Supercomputing Applications
• NDIS—Network Driver Interface Specification
• NDPS—Novell Distributed Print Services
• NDS—Novell Directory Services
• NEP—Network Equipment Provider
• NetBIOS—Network Basic Input/Output System
• NetBT—NetBIOS over TCP/IP
• NEXT—Near-End CrossTalk
• NFA—Nondeterministic Finite Automaton
• NFC—Near field communication
• NFS—Network File System
• NGL—aNGeL
• NGSCB—Next-Generation Secure Computing Base
• NI—National Instruments
• NIC—Network Interface Controller
• NIM—No Internal Message
• NIO—Non-blocking I/O
• NIST—National Institute of Standards and Technology
• NLE—Non-Linear Editing system
• NLP—Natural Language Processing
• NLS—Native Language Support
• NMI—Non-Maskable Interrupt
• NNTP—Network News Transfer Protocol
• NOC—Network Operations Center
• NOP—No OPeration
• NOS—Network Operating System
• NP—Nondeterministic Polynomial time
• NPL—Netscape Public License
• NPTL—Native POSIX Thread Library
• NPU—Network Processing Unit
• NS—Netscape
• NSA—Network Security Appliance
• NSI—Network Service Interface
• NSPR—Netscape Portable Runtime
• NSS—Novell Storage Service
• NSS—Network Security Services
• NSS—Name Service Switch
• NT—New Technology
• NTFS—NT Filesystem
• NTLM—NT Lan Manager
• NTP—Network Time Protocol
• NUMA—Non-Uniform Memory Access
• NURBS—Non-Uniform Rational B-Spline
• NVR—Network Video Recorder
• NVRAM—Non-Volatile Random Access Memory

  O

• OASIS—Organization for the Advancement of Structured Information Standards
• OAT—Operational Acceptance Testing
• OBSAI—Open Base Station Architecture Initiative
• ODBC—Open Database Connectivity
• OEM—Original Equipment Manufacturer
• OES—Open Enterprise Server
• OFDM—Orthogonal Frequency Division Multiplexing
• OFTC—Open and Free Technology Community
• OID—Object Identifier
• OLAP—Online Analytical Processing
• OLE—Object Linking and Embedding
• OLED—Organic Light Emitting Diode
• OLPC—One Laptop per Child
• OLTP—Online Transaction Processing
• OMF—Object Module Format
• OMG—Object Management Group
• OMR—Optical Mark Reader
• OO—Object-Oriented
• OO—OpenOffice
• OOE—Out-of-Order Execution
• OOM—Out Of Memory
• OOo—OpenOffice.org
• OoOE—Out-of-Order Execution
• OOP—Object-Oriented Programming
• OOTB—Out of the box
• OPML—Outline Processor Markup Language
• ORB—Object Request Broker
• ORM—Object-Relational Mapping
• OS—Open Source
• OS—Operating System
• OSCON—O'Reilly Open Source CONvention
• OSDN—Open Source Development Network
• OSI—Open Source Initiative
• OSI—Open Systems Interconnection
• OSPF—Open Shortest Path First
• OSS—Open Sound System
• OSS—Open-Source Software
• OSS—Operations Support System
• OSTG—Open Source Technology Group
• OUI—Organisationally Unique Identifier

  P

• P2P—Peer-To-Peer
• PaaS—Platform as a Service
• PAN—Personal Area Network
• PAP—Password Authentication Protocol
• PARC—Palo Alto Research Center
• PATA—Parallel ATA
• PBS—Portable Batch System
• PC—Personal Computer
• PCB—Printed Circuit Board
• PCB—Process Control Block
• PC DOS—Personal Computer Disc Operating System
• PCI—Peripheral Component Interconnect
• PCIe—PCI Express
• PCI-X—PCI Extended
• PCL—Printer Command Language
• PCMCIA—Personal Computer Memory Card International Association
• PCM—Pulse-Code Modulation
• PCRE—Perl Compatible Regular Expressions
• PD—Public Domain
• PDA—Personal Digital Assistant
• PDF—Portable Document Format
• PDH—Plesiochronous Digital Hierarchy
• PDP—Programmed Data Processor
• PE—Physical Extents
• PERL—Practical Extraction and Reporting Language
• PFA—Please Find Attachment
• PG—Peripheral Gateway
• PGA—Pin Grid Array
• PGA—Programmable Gate Array
• PGO—Profile-Guided Optimization
• PGP—Pretty Good Privacy
• PHP—Hypertext Preprocessor
• PIC—Peripheral Interface Controller
• PIC—Programmable Interrupt Controller
• PID—Proportional-Integral-Derivative
• PID—Process ID
• PIM—Personal Information Manager
• PINE—Program for Internet News and Email
• PIM—Platform Independent Model
• PIO—Programmed Input/Output
• PKCS—Public Key Cryptography Standards
• PKI—Public Key Infrastructure
• PLC—Power Line Communication
• PLC—Programmable Logic Controller
• PLD—Programmable Logic Device
• PL/I—Programming Language One
• PL/M—Programming Language for Microcomputers
• PL/P—Programming Language for Prime
• PLT—Power Line Telecommunications
• PMM—POST Memory Manager
• PNG—Portable Network Graphics
• PnP—Plug-and-Play
• PNRP—Peer Name Resolution Protocol
• PoE—Power over Ethernet
• POID—Persistent Object Identifier
• POJO—Plain Old Java Object
• POP—Point of Presence
• POP3—Post Office Protocol v3
• POSIX—Portable Operating System Interface, formerly IEEE-IX
• POST—Power-On Self Test
• PPC—PowerPC
• PPI—Pixels Per Inch
• PPP—Point-to-Point Protocol
• PPPoA—PPP over ATM
• PPPoE—PPP over Ethernet
• PPTP—Point-to-Point Tunneling Protocol
• PR—Pull Request
• PS—PostScript
• PS/2—Personal System/2
• PSA—Professional Services Automation
• PSM—Platform Specific Model
• PSU—Power Supply Unit
• PSVI—Post-Schema-Validation Infoset
• PTS-DOS—PhysTechSoft - Disk Operating System
• PV—Physical Volume
• PVG—Physical Volume Group
• PVR—Personal Video Recorder
• PXE—Preboot Execution Environment
• PXI—PCI eXtensions for Instrumentation

  Q

• QDR—Quad Data Rate
• QA—Quality Assurance
• QFP—Quad Flat Package
• QoS—Quality of Service
• QOTD—Quote of the Day
• Qt—Quasar Toolkit
• QTAM—Queued Teleprocessing Access Method
• QSOP—Quarter Small Outline Package
• qWave—Quality Windows Audio/Video Experience

  R

• RACF—Resource Access Control Facility
• RAD—Rapid Application Development
• RADIUS—Remote Authentication Dial In User Service
• RAID—Redundant Array of Independent Disks
• RAII—Resource Acquisition Is Initialization
• RAIT—Redundant Array of Inexpensive Tapes
• RAM—Random Access Memory
• RARP—Reverse Address Resolution Protocol
• RAS—Reliability, Availability and Serviceability
• RAS—Remote access service
• RC—Region Code
• RC—Release Candidate
• RC—Run Commands
• RCA—Root Cause Analysis
• RCS—Revision Control System
• RD—Remote Desktop
• rd—remove directory
• RDBMS—Relational Database Management System
• RDC—Remote Desktop Connection
• RDF—Resource Description Framework
• RDM—Relational Data Model
• RDOS—Real-time Disk Operating System
• RDP— Remote Desktop Protocol
• RDS—Remote Data Services
• REFAL—Recursive Functions Algorithmic Language
• REP—RAID Error Propagation
• REST—Representational State Transfer
• regex—Regular Expression
• regexp—Regular Expression
• RF—Radio Frequency
• RFC—Request For Comments
• RFI—Radio Frequency Interference
• RFID—Radio Frequency Identification
• RGB—Red, Green, Blue
• RGBA—Red, Green, Blue, Alpha
• RHL—Red Hat Linux
• RHEL—Red Hat Enterprise Linux
• RIA—Rich Internet Application
• RIAA—Recording Industry Association of America
• RIP—Raster Image Processor
• RIP—Routing Information Protocol
• RIR—Regional Internet registry
• RISC—Reduced Instruction Set Computer
• RISC OS—Reduced Instruction Set Computer Operating System
• RJE—Remote Job Entry
• RLE—Run-Length Encoding
• RLL—Run-Length Limited
• rmdir—remove directory
• RMI—Remote Method Invocation
• RMS—Richard Matthew Stallman
• ROM—Read Only Memory
• ROMB—Read-Out Motherboard
• ROM-DOS—Read Only Memory - Disk Operating System
• RPA-Robotic Process Automation
• RPC—Remote Procedure Call
• RPG—Report Program Generator
• RPM—RPM Package Manager
• RRAS—Routing and Remote Access Service
• RSA—Rivest Shamir Adleman
• RSI—Repetitive Strain Injury
• RSS—Radio Service Software
• RSS—Rich Site Summary, RDF Site Summary, or Really Simple Syndication
• RTAI—Real-Time Application Interface
• RTC—Real-Time Clock
• RTE—Real-Time Enterprise
• RTEMS—Real-Time Executive for Multiprocessor Systems
• RTL—Right-to-Left
• RTMP—Real Time Messaging Protocol
• RTOS—Real-Time Operating System
• RTP—Real-time Transport Protocol
• RTS—Ready To Send
• RTSP—Real Time Streaming Protocol
• RTTI—Run-time Type Information
• RWD—Responsive Web Design

  S

• SaaS—Software as a Service
• SASS—Syntatically Awesome Style Sheets
• SAM— Security Account Manager
• SAN—Storage Area Network
• SAS—Serial attached SCSI
• SATA—Serial ATA
• SAX—Simple API for XML
• SBOD—Spinning Beachball of Death
• SBP-2—Serial Bus Protocol 2
• sbin—superuser binary
• sbs—Small Business Server
• SBU—Standard Build Unit
• SCADA—Supervisory Control And Data Acquisition
• SCID—Source Code in Database
• SCM—Software Configuration Management
• SCM—Source Code Management
• SCP—Secure Copy
• SCPC—Single Channel Per Carrier
• SCPI—Standard Commands for Programmable Instrumentation
• SCSA—Secure Content Storage Association
• SCSI—Small Computer System Interface
• SCTP—Stream Control Transmission Protocol
• SD—Secure Digital
• SDDL—Security Descriptor Definition Language
• SDH—Synchronous Digital Hierarchy
• SDI—Single Document Interface
• SEC—Single Edge Contact
• SDIO—Secure Digital Input Output
• SDK—Software Development Kit
• SDL—Simple DirectMedia Layer
• SDN—Service Delivery Network
• SDP—Session Description Protocol
• SDR—Software-Defined Radio
• SDRAM—Synchronous Dynamic Random Access Memory
• SDSL—Symmetric DSL
• SE—Single Ended
• SEI—Software Engineering Institute
• SEO—Search Engine Optimization
• SFTP—Secure FTP
• SFTP—Simple File Transfer Protocol
• SFTP—SSH File Transfer Protocol
• SGI—Silicon Graphics, Incorporated
• SGML—Standard Generalized Markup Language
• SGR—Select Graphic Rendition
• SHA—Secure Hash Algorithm
• SHDSL—Single-pair High-speed Digital Subscriber Line
• SIEM—Security information and event management
• SIGCAT—Special Interest Group on CD-ROM Applications and Technology
• SIGGRAPH—Special Interest Group on Graphics
• SIMD—Single Instruction, Multiple Data
• SIMM—Single Inline Memory Module
• SIP—Session Initiation Protocol
• SIP—Supplementary Ideographic Plane
• SISD—Single Instruction, Single Data
• SISO—Single-Input and Single-Output
• SLA-Service Level Agreement
• SLED—SUSE Linux Enterprise Desktop
• SLES—SUSE Linux Enterprise Server
• SLI—Scalable Link Interface
• SLIP—Serial Line Internet Protocol
• SLM—Service Level Management
• SLOC—Source Lines of Code
• SME—Subject Matter Expert
• SMF—Single-Mode Fiber
• SPM—Software project management
• SPMD—Single Program, Multiple Data
• SMA—SubMiniature version A
• SMB—Server Message Block
• SMBIOS—System Management BIOS
• SMIL—Synchronized Multimedia Integration Language
• S/MIME—Secure/Multipurpose Internet Mail Extensions
• SMP—Supplementary Multilingual Plane
• SMP—Symmetric Multi-Processing
• SMPS—Switch Mode Power Supply
• SMS—Short Message Service
• SMS—System Management Server
• SMT—Simultaneous Multithreading
• SMTP—Simple Mail Transfer Protocol
• SNA—Systems Network Architecture
• SNMP—Simple Network Management Protocol
• SNTP—Simple Network Time Protocol
• SOA—Service-Oriented Architecture
• SOAP—Simple Object Access Protocol
• SOAP—Symbolic Optimal Assembly Program
• SOPA—Stop Online Piracy Act
• SoC—System-on-a-Chip
• SO-DIMM—Small Outline DIMM
• SOE—Standard Operating Environment
• SOHO—Small Office/Home Office
• SOI—Silicon On Insulator
• SP—Service Pack
• SPA—Single Page Application
• SPF—Sender Policy Framework
• SPI—Serial Peripheral Interface
• SPI—Stateful Packet Inspection
• SPARC—Scalable Processor Architecture
• SQL—Structured Query Language
• SRAM—Static Random Access Memory
• SSA—Static Single Assignment
• SSD—Software Specification Document
• SSD—Solid-State Drive
• SSDP—Simple Service Discovery Protocol
• SSE—Streaming SIMD Extensions
• SSH—Secure Shell
• SSI—Server Side Includes
• SSI—Single-System Image
• SSI—Small-Scale Integration
• SSID—Service Set Identifier
• SSL—Secure Socket Layer
• SSO—Single Sign On
• SSP—Supplementary Special-purpose Plane
• SSSE—Supplementary Streaming SIMD Extensions
• SSSP—Single Source Shortest Path
• SSTP—Secure Socket Tunneling Protocol
• su—superuser
• SUS—Single UNIX Specification
• SUSE—Software und System-Entwicklung
• SVC—Scalable Video Coding
• SVG—Scalable Vector Graphics
• SVGA—Super Video Graphics Array
• SVD—Structured VLSI Design
• SWF—Shock Wave Flash
• SWT—Standard Widget Toolkit
• Sysop—System operator
• SOLID— Single-responsibility Principle, Open-closed Principle, Liskov substitution principle, Interface segregation principle, Dependency Inversion principle

  T

• TAO—Track-At-Once
• TAPI—Telephony Application Programming Interface
• TASM—Turbo ASseMbler
• TB—TeraByte
• Tcl—Tool Command Language
• TCP—Transmission Control Protocol
• TCP/IP—Transmission Control Protocol/Internet Protocol
• TCU—Telecommunication Control Unit
• TDMA—Time-Division Multiple Access
• TFT—Thin-Film Transistor
• TFTP—Trivial File Transfer Protocol
• TI—Texas Instruments
• TIFF—Tagged Image File Format
• TLA—Three-Letter Acronym
• TLD—Top-Level Domain
• TLS—Thread-Local Storage
• TLS—Transport Layer Security
• TLV—Type-length-value
• tmp—temporary
• TNC—Terminal Node Controller
• TNC—Threaded Neill-Concelman connector
• TPF—Transaction Processing Facility
• TPM—Trusted Platform Module
• TROFF—Trace Off
• TRON—Trace On
• TRON—The Real-time Operating system Nucleus
• TRSDOS—Tandy Radio Shack - Disk Operating System
• TSO—Time Sharing Option
• TSP—Traveling Salesman Problem
• TSR—Terminate and Stay Resident
• TTA—True Tap Audio
• TTF—TrueType Font
• TTL—Transistor-Transistor Logic
• TTL—Time To Live
• TTS—Text-to-Speech
• TTY—Teletype
• TUCOWS—The Ultimate Collection of Winsock Software
• TUG—TeX Users Group
• TWAIN—Technology Without An Interesting Name

  U

• UAAG—User Agent Accessibility Guidelines
• UAC—User Account Control
• UART—Universal Asynchronous Receiver/Transmitter
• UAT—User Acceptance Testing
• UB—Undefined Behavior
• UCS—Universal Character Set
• UDDI—Universal Description, Discovery, and Integration
• UDMA—Ultra DMA
• UDP—User Datagram Protocol
• UEFI—Unified Extensible Firmware Interface
• UHF—Ultra High Frequency
• UI—User Interface
• UL—Upload
• ULA—Uncommitted Logic Array
• UMA—Upper Memory Area
• UMB—Upper Memory Block
• UML—Unified Modeling Language
• UML—User-Mode Linux
• UMPC—Ultra-Mobile Personal Computer
• UMTS—Universal Mobile Telecommunications System
• UNC—Universal Naming Convention
• UNIVAC—Universal Automatic Computer
• UPS—Uninterruptible Power Supply
• URI—Uniform Resource Identifier
• URL—Uniform Resource Locator
• URN—Uniform Resource Name
• USB—Universal Serial Bus
• :/usr|usr—user
• USR—U.S. Robotics
• UTC—Coordinated Universal Time
• UTF—Unicode Transformation Format
• UTP—Unshielded Twisted Pair
• UTRAN—Universal Terrestrial Radio Access Network
• UUCP—Unix to Unix Copy
• UUID—Universally Unique Identifier
• UUN—Universal User Name
• UVC—Universal Virtual Computer
• UWP—Universal Windows Platform
• UX—User Experience

  V

• var—variable
• VAX—Virtual Address eXtension
• VCPI—Virtual Control Program Interface
• VB—Visual Basic
• VBA—Visual Basic for Applications
• VBS—Visual Basic Script
• VDI—Virtual Desktop Infrastructure
• VDU— Visual Display Unit
• VDM— Virtual DOS machine
• VDSL—Very High Bitrate Digital Subscriber Line
• VESA—Video Electronics Standards Association
• VFAT—Virtual FAT
• VHD — Virtual Hard Disk
• VFS—Virtual File System
• VG—Volume Group
• VGA—Video Graphics Array
• VHF—Very High Frequency
• VLAN—Virtual Local Area Network
• VLSM—Variable Length Subnet Mask
• VLB—Vesa Local Bus
• VLF—Very Low Frequency
• VLIW—Very Long Instruction Word
• VLSI—Very-Large-Scale Integration
• VM—Virtual Machine
• VM—Virtual Memory
• VMM—Virtual Machine Monitor
• VNC—Virtual Network Computing
• VOD—Video On Demand
• VoIP—Voice over Internet Protocol
• VPN—Virtual Private Network
• VPS—Virtual Private Server
• VPU—Visual Processing Unit
• VR—Virtual Reality
• VRML—Virtual Reality Modeling Language
• VSAM—Virtual Storage Access Method
• VSAT—Very Small Aperture Terminal
• VT—Video Terminal?
• VTL— Virtual Tape Library
• VTAM—Virtual Telecommunications Access Method
• VRAM—Video Random Access Memory

  W

• W3C—World Wide Web Consortium
• WWDC—Apple World Wide Developer Conference
• WAFS—Wide Area File Services
• WAI—Web Accessibility Initiative
• WAIS—Wide Area Information Server
• WAN—Wide Area Network
• WAP—Wireless Access Point
• WAP—Wireless Application Protocol
• WASM—Watcom ASseMbler
• WBEM—Web-Based Enterprise Management
• WCAG—Web Content Accessibility Guidelines
• WCF—Windows Communication Foundation
• WDM—Wavelength-Division Multiplexing
• WebDAV—WWW Distributed Authoring and Versioning
• WEP—Wired Equivalent Privacy
• WFI—Wait For Interrupt
• WiMAX—Worldwide Interoperability for Microwave Access
• WinFS—Windows Future Storage
• WinRT—Windows RunTime
• WINS—Windows Internet Name Service
• WLAN—Wireless Local Area Network
• WMA—Windows Media Audio
• WMI— Windows Management Instrumentation
• WMV—Windows Media Video
• WNS—Windows Push Notification Service
• WOL—Wake-on-LAN
• WOR—Wake-on-Ring
• WORA—Write once, run anywhere
• WORE—Write once, run everywhere
• WPA—Wi-Fi Protected Access
• WPAD—Web Proxy Autodiscovery Protocol
• WPAN—Wireless Personal Area Network
• WPF—Windows Presentation Foundation
• WS-D—Web Services-Discovery
• WSDL—Web Services Description Language
• WSFL—Web Services Flow Language
• WUSB—Wireless Universal Serial Bus
• WWAN—Wireless Wide Area Network
• WWID—World Wide Identifier
• WWN—World Wide Name
• WWW—World Wide Web
• WYSIWYG—What You See Is What You Get
• WZC—Wireless Zero Configuration

  X

• XAG—XML Accessibility Guidelines
• XAML—eXtensible Application Markup Language
• XDM—X Window Display Manager
• XDMCP—X Display Manager Control Protocol
• XCBL—XML Common Business Library
• XHTML—eXtensible Hypertext Markup Language
• XILP—X Interactive ListProc
• XML—eXtensible Markup Language
• XMMS—X Multimedia System
• XMPP—eXtensible Messaging and Presence Protocol
• XMS—Extended Memory Specification
• XNS—Xerox Network Systems
• XP—Cross-Platform
• XP—Extreme Programming
• XPCOM—Cross Platform Component Object Model
• XPI—XPInstall
• XPIDL—Cross-Platform IDL
• XPS— XML Paper Specification
• XSD—XML Schema Definition
• XSL—eXtensible Stylesheet Language
• XSL-FO—eXtensible Stylesheet Language Formatting Objects
• XSLT—eXtensible Stylesheet Language Transformations
• XSS—Cross-Site Scripting
• XTF—eXtensible Tag Framework
• XTF—eXtended Triton Format
• XUL—XML User Interface Language
• XVGA—Extended Video Graphics Adapter

  Y

• Y2K—Year Two Thousand
• YAAF—Yet Another Application Framework
• YACC—Yet Another Compiler Compiler
• YAML—YAML Ain't Markup Language
• YARN—Yet Another Resource Negotiator
• YaST—Yet another Setup Tool

  Z

• ZCAV—Zone Constant Angular Velocity
• ZCS—Zero Code Suppression
• ZIF—Zero Insertion Force
• ZIFS—Zero Insertion Force Socket
• ZIP—ZIP file archive
• ZISC—Zero Instruction Set Computer
• ZOI—Zero One Infinity
• ZOPE—Z Object Publishing Environment
• ZMA—Zone Multicast Address
• ZPL—Z-level Programming Language