ADSL Asymmetric Digital Subscriber Line (form of DSL)
AFAIK (as far as I know; email)
AGP Advanced Graphics Port
AIM AOL Instant Messenger
ALT. ALTernate lifestyle (USENET newsgroup category)
ANSI American National Standards Institute
AOL America Online
ARQ Automatic Repeat Request
ASCII American Standard Code for Information Interchange
ASP Association of Shareware Professionals
ASPI Advanced SCSI Programming Interface [Adaptec]
ATA Advanced Technology Attachment (original hard drive interface)
ATDT Attention Dial Tone (modem command)
ATM Adobe Typeface Manager + Asynchronous Transfer Mode
ATZ Attention Restore configuration profile from nonvolatile RAM (modem command)
Autoexec Automatic Execution file (AUTOEXEC.BAT automatically executed on startup of DOS systems)
AWK (Unix language named after its authors... Al Aho, Peter Weinberger and Brian Kernighan)
B2B Business to Business
BDSL Broadband DSL
BEDO Burst Extended Data Out (RAM)
BIOS Basic Input/Output System (system chips)
BPS Bits Per Second + Bytes Per Second
BsoD Blue (or black) Screen of Death: Windows just died (again)
CAD Computer Aided Design
CADD Computer Aided Design and Drafting
CC: Carbon Copy (email usage)
CCITT Comite Consultatif International Telegraphique et Telephonique/
Consultative Committee for International Telegraph and Telephone
CD Change Directory (UNIX/DOS)
CD-R Compact Disk - Recordable 
CD0R/W Compact Disk - Rewritable
CD-ROM Compact Disk - Read Only Memory
CD-WO Compact Disk - Write Once
CD-XA Compact Disk - Extended Architecture
CDMA Code-Division Multiple Access (wireless/cellphone protocol)
CDPD Cellular Digital Packet Data (wireless protocol)
CERN The European Particle Physics Laboratory (initials originally from Conseil European pour la Recherche Nucleaire)
CERT Computer Emergency Response Team)
CGI-BIN Common Gateway Interface - Binary (programming for Web forms)
CIS CompuServe Information Service 
CMOS Complementary Metal-Oxide Semiconductor (type of nonvolatile memory chip) + PC configuration stored on CMOS
CMYK Cyan-Magenta-Yellow-Black (color model)
COAX Coaxial Cable (for Ethernet and similar networks)
COM1 First serial Port (asynchronous port)
COM2 Second serial Port
COMDEX Computer Dealers Exposition (biggest yearly U.S. computer show)
CRT Cathode Ray Tube: standard type computer monitor display
CPU Central Processing Unit
CSID Call Subscriber ID (for FAX and phone caller ID)
CSLIP Compressed Serial Line Interface Protocol [Internet]
CSV Comma-Separated Value/Variable (file type)
CTRL Control (computer keyboard key)
CYMK Cyan-Yellow-Magenta-Black (color model)
DAC Data Acquisition and Control + Digital to Analog Converter
dB Decibel
DBMS Data Base Management System
DCD Data Carrier Detect
DCE Data Communications Equipment + Distributed Computing Environment [OSF] + Distributed Computing Equipment
DCF Data Communication Facility [IBM] +
DDE Direct Data Entry + Dynamic Data Exchange [Microsoft]
DDR Double Data Rate (double=speed of RAM)
DDR-SDRAM Double Data Rate-SDRAM
DIMM Dual Inline Memory Module
DIN Deutsche Industrie Norm (German equivalent of EIA)
DIP Dual In-line Package (e.g., DIP switches)
DIR Directory (file)
DLL Dynamic Link Library
DMA Direct Memory Access/Addressing
DNS Domain Naming System (Internet address names)
DOS Disk Operating System
DPI Dots Per Inch
DRAM Dynamic Random Access Memory 
DSL Digital Subscriber Line: fast Internet connection over existing phone lines
DSTN Double Supertwisted Nematic (LCD screen type)
DTMF Dual Tone Multiple Frequency (phone tones)
DUN Dial-Up Networking (Microsoft)
DVD Digital Video Disk; Digital Versatile Disk; 4.7 GB CD format
EBCDIC Extended Binary Coded Decimal Interchange Code [IBM] (is to ASCII as Sanskrit is to English)
ECC Error Check Code + Error Checking and Correction + Error Correction Code
ECP Enhanced Capabilities Port [Microsoft]
EDO Extended Data Out (RAM)
EEPROM Electrically Erasable Programmable Read-Only Memory
EIDE Enhanced Integrated Drive Electronics (hard drive interface)
EISA Extended Industry Standard Architecture (PC bus design)
EMACS Editing Macros [Unix editor]
EOF End of File (^Z character)
EPP Enhanced Parallel Port
EPROM Electrically Programmable Read Only Memory + Erasable Programmable Read Only Memory
ESDI Enhanced Small Device Interface
EWAN Emulator Without A Good Name [Internet]
FAQ Frequently Asked Question
FAT File Allocation Table
FDC Floppy Disk Controller
FDISK Fixed Disk (DOS utility)
FIFO First-In, First-Out
Firewire IEEE 1394 serial port (faster than USB)
FLOPS Floating Point Operations/Second
FPM Fast Page Mode (RAM)
FYI For Your Information
GIGO Garbage In, Garbage Out
GIS Geographic Information System
GNU Gnu's Not Unix (operating system that really IS Unix)
GPS Global Positioning Satellite/System
GUI Graphical User Interface
GW-basic Gee Whiz BASIC
HDSL High-Data-Rate Digital Subscriber Line (DSL) + High-Speed Digital Subscriber Loop
HDTV High Definition Television
HEX Hexadecimal
HP Hewlett-Packard (Company)
HPFS High-Performance File System (Windows NT)
HPGL Hewlett-Packard Graphics Language
HPIB Hewlett-Packard Interface Bus
HPLJ Hewlett-Packard Laser Jet
HSV Hue Saturation Value (color model)
HTML HyperText Markup Language
HTTP HyperText Transport Protocol
HTTP-NG HTTP Next Generation
HTTPS HyperText Transfer Protocol Secure
Hz Hertz (frequency, per second)
IDE Integrated Development Environment [Borland] + Integrated Drive Electronics + Intelligent Drive Electronics
IEEE 1394 Firewire (faster serial port than USB)
IMAP Internet Message Access Protocol [Internet; a step up from POP]
IMHO (in my humble opinion; email)
I/O Input/Output (serial and parallel ports)
IP Internet Protocol (as in TCP/IP)
IPX Internetwork Packet Exchange [Novell]
IR Infrared 
IrDA Infrared Data Association (Ir port standard)
IRQ Interrupt Request (PC hardware signal)
ISA Industry Standard Architecture
ISDN Integrated Services Digital Network (digital phone line)
ISP Internet Service Provider
IT Information Technology 
I-WAY Information Highway 
JPEG Joint Photographic Experts Group
KB Keyboard + Kilobyte (1,024 bytes; also kB)
kHz Kilohertz
LAN Local Area Network 
LCD Liquid Crystal Display
LED Light Emitting Diode
LF Line Feed
LIF Low Insertion Force
LINUX (Free-Source version of UNIX Operating system named after Linus Torvalds)
listserv List Server [Internet]
LPI Lines Per Inch 
LPT Line Printer
LPT1 First Parallel Printer Port
LPT2 Second Parallel Printer Port
LQ Letter Quality 
LSI Large Scale Integration 
LZW Lempel-Ziv-Walsh (algorithm)
MB Megabyte (also mB; 1,000 kilobytes)
MBASIC Microsoft BASIC [Microsoft]
MBps Megabytes Per Second
Mbps Megabits Per Second 
MD Make Directory (DOS/Unix)
MEG Megabyte
MFS Macintosh File System [Macintosh] 
MHz Megahertz (million cycles per second)
MIDI Musical Instrument Digital Interface
MIME Multipurpose Internet Mail Extension [email attachment protocol]
MIPS Million Instructions Per Second
MMX Multimedia Extensions (additional CPU instructions)
MODEM Modulator Demodulator
MPC Multimedia Personal Computer (Microsoft)
MPEG Moving Picture Experts Group
MSCDEX Microsoft Compact Disc Extension
MS-DOS Microsoft - Disk Operating System
MSG Message 
MSIE Microsoft Internet Explorer [Microsoft]
MTBF Mean Time Between Failures
NCSA National Center for Supercomputing Applications
NICAD Nickel Cadmium
NIMH Nickel-Metal Hydride
NNTP Network News Transfer Protocol [Internet]
NSFNET National Science Foundation Network
OCX OLE Custom Control 
OLE Object Linking and Embedding [Microsoft]
PBSRAM Pipeline Burst RAM
PC-DOS Personal Computer - Disk Operating System [IBM]
PCI Peripheral Component Interconnect/Interface (PC Bus)
PCMCIA Personal Computer Memory Card International Association
PD Public Domain
PDA Personal Digital Assistant
PGP Pretty Good Privacy (name of encryption program)
PIM Personal Information Manager
PING Packet Internet Groper
PIXEL Picture Element
POP Post Office Protocol (protocol for distributing email)
Popmail email via POP
PPM Pages Per Minute 
PRN Printer
PRTSC Print Screen
RAM Random Access Memory
RDRAM Rambus Dynamic Random Access Memory 
RGB Red-Green-Blue (color model)
REM Remark (comment)
RISC Reduced Instruction Set Computer 
RJ-11 Standard U.S. phone connector
RJ-45 Standard Ethernet connector
RAID Redundant Arrays of Independent Disks + Redundant Arrays of Independent Drives + Redundant Arrays of Inexpensive Disks
RIMM Rambus Inline Memory Module
RLL Run Length Limited (encoding scheme for hard disks)
RLSI Ridiculously Large-Scale Integration 
RMA Return Material Authorization + Return to Manufacturer Authorization
RMDIR Remove Directory (DOS/Unix)
RN Read News [Internet]
ROM Read Only Memory (chip)
ROTFL (rolling on the floor laughing; email)
SCSI Small Computer System Interface (for hard drives, scanners, etc.)
SDRAM Synchronous Dynamic Random Access Memory 
SGML Standard Generalized Markup Language 
SGRAM Synchronous Graphics RAM
SIMM Single In-line Memory Module
SIPP Single In-line Pin Package
SLIP Serial Line Interface Protocol
SMTP Simple Mail Transfer Protocol (basic email protocol)
SNOBOL String Oriented Symbolic Language (Programming Language)
SO-DIMM Small Outline DIMM
SRAM Static Random Access Memory 
SSL Secure Sockets Layer
SVGA Super Video Graphics Array 
SYSOP System Operator
TCP/IP Transmission Control Protocol/Internet Protocol
TDMA Tone-Division Multiple Access wireless/cellphone protocol 
TEMP Temporary
Thomas The (U.S.) House (of Representatives) Open Multimedia Access System
TIFF Tagged Image File Format
TMP Temporary
TWAIN Technology Without Any Interesting Name (connection between application and scanner software)
UAE Unrecoverable Application Error
UART Universal Asynchronous Receiver/Transmitter
UDMA Ultra Direct Memory Access
UMB Upper Memory Block [LIM/AST]
UNIX (AT&T Bell Laboratories Operating System)
UPS Uninterruptible Power Supply
USB Universal Serial Bus serial port standard
USENET User's Network [Internet]
UUCP Unix-To-Unix Copy Program
UXGA Ultra XGA; see XGA; 1600x1200 pixels
VAX/VMS Virtual Address Extension/Virtual Memory System [DEC]
VDT Video Dial Tone + Video Display Terminal
VFAT Virtual File Allocation Table [Microsoft]
VGA Video Graphics Array: IBM/Windows 640x480 color graphics display standard
VRAM Video Random Access Memory
VxD Virtual Extended Driver [Microsoft]
WAIS Wide Area Information Server
WFW Windows For Workgroups [Microsoft]
Winword Word For Windows [Microsoft]
WORM Write Once, Read Many
WP WordPerfect + Word Processing + Write Protected
WPM Words Per Minute
WRAM Windows RAM (graphics card)
WS WordStar + Workstation
WYSIWYG What You See Is What You Get
XGA Extended Graphics Array [IBM]: generically, 1024x768 color standard
ZIF Zero-Insertion Force (socket)
*.* Star-Dot-Star (represents any file name, any file name extension)
.ARC Archive (file name extension)
.ARJ Compressed File (file name extension) [Jung]
.ASC ASCII text (file name extension)
.ASP Active Server Page (Microsoft)
.ASM Assembler Source Language 
.BAK Backup 
.BAS Basic Language 
.BAT Batch Processing 
.BIN Binary 
.BMP Bitmap Picture 
.CFG Configuration 
.CGM Computer Graphics Metafile +
.COM Command 
.DAT Data 
.DIC Dictionary 
.DOC Document + Documentation (file name extensions)
.DRV Device Driver (Also see .DVR)
.EPS Encapsulated PostScript 
.HLP Help 
.HQX BinHexed [Macintosh]
.ICO Icon 
.IDX Index 
.INI Initialize 
.JPG Joint Photographic Experts Group (compressed graphics format)
.ME Usually Read.ME
.MP3 MPEG 3 compressed audio
.NDX Index 
.OLD Old version 
.OVL Program Overlay 
.OVR Program Overlay 
.PAS PASCAL source code 
.PCT Picture 
.PCX Picture Image 
.PDF Portable Document Format (Adobe Acrobat) + Printer Description [Borland,Lotus]
.PFM Printer Font Metrics [Windows]
.RTF Rich Text Format
.SCR Script 
.SEA Self Extracting Archive [Macintosh]
.STY Style [Ventura, Word, WordPerfect]
.SYS System Configuration +
.tar Tape Archive (archived file name extension) [Unix]
.tar.Z Compressed Archived files [Unix]
.TIF Tagged Image File (filename extension)
.TMP Temporary
.TTF TrueType Font 
.UUE UUEncoding [Unix]
.VXD Virtual device Driver (Windows)
.WAV Waveform Audio 
.WMF Windows Metafile Format [Microsoft]
.WPG WordPerfect Graphics 
.WRI Write 
.z Packed file (file name extension - using Pack/Unpack program) lower case z..[Unix]
.Z Compressed file (file name extension - using Compress/Uncompress program)..upper case Z..[Unix]
.ZIP Compressed File [PKWare]
.$$$ Temporary File