0-9
1337 – From the word Leet, derived from the word elite
2 – too, or to
4 – For

A
AFAICR/S/T – As far as I can recall / remember / see / tel
AFAIK – As far as I know
AFK – Away from keyboard
ANFSCD – And Now For Something Completely Different. Used to change the subject of conversation.
ASAP – As soon as possible
ASL – Age / sex / location
ATEOTD – At The End of the Day
ATM – At the moment
AWOL – Absent Without (Official) Leave
AYBABTU (also abbreviated as AYB) – All your base are belong to us (from the video game Zero Wing)

B
B2B – Business to Business
B& and/or B7- Banned
BBIAB – Be back in a bit
BBL/S – Be back later / shortly / soon
BCNU – Be seein’ you
Blog – Also known as web log or an online journal
BOFH – ~censored~ operator from hell
Bot – Any type of automated software in chatrooms and web-cataloging software
BRB – Be right back
BSOD – Blue Screen of Death
BTDT – Been there done that
BTW – By the way
Bump – Increment (For example, C’s ++ operator.)or a backronym for “Bring Up My Post”

C
Crawl – To retrieve a web page along with the hyperlinks that reference it
Crapplet – A poorly written computer application
CU – See you (later)
CYA – See ya OR Cover Your Ass
Cyber (prefix) – A term used to connect the subsequent word loosely to the world of computers or the Internet or sex over a computer
Cyberspace – Virtual reality, the Internet, the World Wide Web, and other kinds of computer systems. Science fiction author William Gibson popularized the term in his novel Neuromancer. Gibson used the word to describe a virtual world of computer networks that his cyberpunk heroes ‘jacked into’

D
DFTT – Don’t feed the trolls
DGAF – Don’t Give A ~censored~
DIAF – Die in a fire
DILLIGAF/D/S – Does it look like I give a flip / ~censored~ / damn / ~love~
DND – Do not disturb
DOA – Dead on arrival. Refers to hardware that is broken on delivery.

E
EOF – End Of File
EOM – End of Message
EOL – End of Life. Device or hardware that is at the end of its product life cycle.
EQ – EverQuest
ETA – Estimated time of arrival
Ok, EverQuest might be a little bit strange here. It's an old online MMORPG that used to be very popular. Before WOW.

F
FAQ – Frequently Asked Question(s)
FFS – For ~censored~’s sake
Flamer – Someone who makes inflammatory, abusive or directly offensive comments. Similar to, but not quite the same as an Internet troll[3]
FMCDH – From My Cold Dead Hands
FOAD – ~censored~ off and die
FOAF – Friend of a friend
FTL – For the loss
FTW – For the win
FU – ~censored~ you
FUBAR – ~censored~ up beyond all recognition / repair (from military slang; pronounced “foo-bar”)
FUD – Fear, Uncertainty and Doubt (the purposeful spread of misinformation)
FWIW – For what it’s worth
FYI – For your information

G
GBTW – Get back to work
GF – Great/good fight/girlfriend
GFU – Good for you
GFY – Go ~censored~ yourself
GG – Good game, used at or near the conclusion of a gaming match
GJ – Good job, often used in online gaming when a teammate performs an act benefitting his team, such as killing an opponent or enabling that kill
GMTA – Great minds think alike
Godwin’s Law – Dictates that the longer a thread, the more likely someone will post a comparison involving Nazis or Hitler
Gratz – Congratulations
GTFO – Get the ~censored~ out
GTG or G2G – ‘Got to go’ or ‘Good to go’
GR -Good Race
GR8 – Great

H
HAND – Have A Nice Day
Handle – Name used in online chat, (AKA nick(name), alias, screen/user name)
HF – Have fun
Haxor or H4x0r (1337) – Hacker
Hit – A request made to the web server, (noun) the results of an internet search, (verb) loading a Web page. Hits are not equivalent to visitors of a webpage.
Home page – The website’s introduction page, starting point, and guide. The technical term is “index”
Hot list – A collection of publicly available URLs (World Wide Web site addresses), sometimes available as text files.
HTH – Hope this / that helps
H8 – Hate

J
Jaggy – Aliased computer graphics
JK or j/k – Just kidding, or joke
JFGI – Just ~censored~/Freaking Google It
K
k or kk – OK
KISS – Keep it simple stupid.
KS(ing) – Kill-Steal(ing)
KOS – Kill on sight
KTHX – OK, thanks
KTHXBAI or KTHXBYE – OK, thanks, goodbye, used either to cut short a conversation or to express displeasure with being cut short

L
L2P – Learn to play; an admonishment to MMORPG players who are incompetent and/or whine
L8R – Later, L8R also sometimes abbreviated as L8ER is commonly used in chat rooms and other text based communications as a way of saying good bye.
Lag – Slang term for slow Internet speeds or high Internet latency; Lag is sometimes due to a server problem, but more frequently due to the connection between client and server. A slow or intermittent connection may often be referred to as laggy
Lamer – A know-nothing, one who is lame.
Leet – Often spelled as l33t or 1337 in ASCII form. It originally meant elite
LFG – Looking for group
LFM – Looking for more
LM(F)AO – Laughing my (frigging) ass off
LMIRL – Let’s meet in real life.
LMK – Let me know
LOL – Laughing out loud, laugh out loud
LTNS – Long time no see
Lurker – Someone who frequents a Usenet group without participating in discussions

M
MMORPG, MMO – Massive Multi-player Online Role Playing Game
MMOFPS – Massive Multi-player Online First Person Shooter
MOTD – Message of the day
MS – MapleStory, an MMORPG
MTFBWY – May The Force be with you
MUD – Multi-User Dungeon
MUSH – Multi-User Shared Hallucination
MYOB – Mind your own business
M8 – Mate
N
NE1 – “Anyone”
NFI – “No ~censored~ Idea”
Newbie, noob, or n00b – An inexperienced user of a system or game,or an annoying person.
NIFOC – Naked In Front Of Computer
NM – (Sometimes written N/M) Not much, Never mind or no message, used on message boards or in e-mails to indicate that everything is already said in the subject line.
NP – No problem
NSFW – Not safe for work. Warning about content that may get the viewer in trouble with his employer or co-workers.
NVM, NVMD, or nm – Nevermind, not much

O
O RLY – Oh really?
OIC – Oh, I see
OFN – Old ~censored~ news
OMG – Oh my god
OMFG – Oh my ~censored~ god
OMW – On my way or Oh my word
OP – Original poster / Operator / Outpost
OS – Operating system
OT – Off topic
OTOH – On the other hand
OTP – On the phone or One true pairing

P
P2P – Peer to peer, or pay to play
PAW – Parents are watching
PEBKAC/PEBCAK – Problem exists between keyboard and chair
Ping – From the popular network monitoring tool, used as a greeting similar to “Are you there?”.
PITA – Pain in the arse / ass
PLMK – Please let me know
PMSL – Pissing myself laughing
POS – Piece of ~love~, or parent over shoulder.
POTS – Plain old telephone service
POV – Point of view
PPL – People
PTKFGS – Punch the Keys For God’s Sake
pr0n – Intentional misspelling of porn
PW – Persistent World (gaming)
pwned – Intentional misspelling of owned