Chat Lingo

Phr0z3n.Dev's Chart Of Chat Lingo/Acronyms
Acronym/Lingo Meaning
0-day geek: (computer) vulnerability (that developers have zero day (a.k.a. no time) to fix)
1337 geek: (leet) spelling for elite (hacker or computer programmer)
2day Today
2ff Too Effing Fabulous, Too Effing Feisty (original)
2moro Tomorrow
2nite Tonight
4ever / 4eva Forever
AFAICR As Far As I Can Remember/Recall
AFIAK As Far As I Know
ALAICR As Long As I Can Remember/Recall
AQAP As Quick(ly) As Possible
ASAP As Soon As Possible
ATM At The Moment
AWS As We Speak
B4 Before
B4N / BfN Bye For Now
b/f Boyfriend
BBIAB (I Will) Be Back In A Bit
BBIAM (I Will) Be Back In A Minute
BF Best Friend
BFF Best Friend(s) Forever
BFFF Best Effing Friend(s) Forever
BFK Big Fat Kiss
BOL Bawl Out Loud
BRB (I Will) Be Right Back
BSOM Beats the $&%* outta me. (as in, "I have no idea" or, "I have no clue".)
BS / B.S. / B/S Bull#&%$ (Swear)
BTW By The Way
Buddy Chat Friend (on your chat client list)
cam Webcam, Web Camera
Chillaxin' Chilling And Relaxing
CTFD Close The Front/Effing Door
CTFD Calm The Eff Down
CTHD Calm The Hell Down
CYA See Ya! (as in insultive BYE!)
CYL See You/Ya Later, Catch You Later (original)
CWYL (I Will) Chat With You Later
D2E Down-To-Earth
D/L Down Low
DFC Don't Effing Care (usually said by delinquents)
DIY Do It Yourself
DL Download (file from the internet)
DnO Down And Out, Down n Out (original)
DoA Dead On Arrival
DoS geek: Denial of Service (Hacking Parlance)
DDoS geek: Distributed Denial of Service (Hacking Parlance)
DWL Dying With Laughter
EFF Epic Effin' Fail'ure
EMG Everything Must Go
f/o @#$% Off (offensive)
FCS For Christ's Sake
FFS For Eff's Sake (Swear)
FTR For The Record
FTSO For The Sake Of
FTTB For The Time Being
FUD Effed Up Decision (original)
FUBAR / FOOBAR Effed Up Beyond All Recognition/Repair (Military)
FUBR Effed Up Beyond Recognition/Repair
FUBU Effed Up Beyond Understanding (not the same as the clothes brand)
FWIW For What It's Worth
FWIK From What I Know
FYI For Your Information/Info.
g/f Girlfriend
GAL Get A Life (original)
GFYS Go Eff Yourself (offensive)
GM / g/m Good Morning
GM? Got Mail?, Got Milk? (offensive)
GMM? Got My Mail?
GR8 Great
GTFO Get The Eff Out
GTFU Get The Eff Up
GTHO Get The Hell Out
GTHU Get The Hell Up
G2G / GTG Got To Go (usually in a hurry)
H&K / HaK / HnK / H+K Hugs And Kisses
hax / |-|/-\>< geek for hack
hax0r geek: pertaining to hacking/hacker (These terms are usually used to circumnavigate authourities', such as the NSA, surveillance on the internet.)
ICU I See You (usually on webcam)
IDFC I Don't Effing Care (usually said by delinquents)
IDK I Don't Know
IM Instant Message/Messaging
IMB In My Book
IMHO In My Humble Opinion
IMO In My Opinion
IMOT In My Own Time
IMVHO In My Very Humble Opinion
ISO In Search Of
j/k Joking, Just Kidding
JIT Just In Time
Kewl! / Kewlies! Cool!: Overwhelmingly expressing liking something, someone, an idea, etc.  This gesture is usually used with a particular emoticon: the one wearing the sunshades.
KIR Keep, Keeping It Real (original)
KISS Keep It Simple, Stupid (usually used by youngsters who are hiding something from someone, especially an adult)
KK OK! OK! (Incessantly Reassuring)
KMT Kiss/Kissing My Teeth
KOTC Kiss On The Cheek
KOTL Kiss On The Lips
KT Kill/Killing Time, Kiss/Kissing Teeth
L8 Late
L8R Later
Lappy Laptop
LMAO Laughing My Ass Off
LMBO Laughing My Balls Off
LMN8 Eliminate
LOL Laugh/Laughing Out Loud
LOLAK Lots Of Love And Kisses
LTNS Long Time No See
Mofo Mother'effer' (As in, "I am a bad ass mofo!")
MILF Mom/Mother I'd Like To Eff (offensive)
MMW Mark My Words
MUNG geek: Mash Until No Good (usually the stack)
NM No Mentioning (It)
N00b / Noob geek: Newbie/Novice/Inexperienced (hacker or computer user)
n/p No Problem
OBTW Oh, By The Way
OIC Oh! I See!
OMDB Over My Dead Body
OMG! Oh My God!, Oh My Gosh!
OMFG Oh My Effing God
OTOH On The Other Hand
P2P geek: Peer-To-Peer (Download), Point-To-Point (Internet Connection)
Pic Picture or image
PM Private Message, Private Chat
PoC Piece Of Crap (Swear)
PoD geek: Ping of Death (hacking parlance)
PoR Point Of Retirement
PoS Point Of Sale, Piece Of $&%* (Swear)
PoV Point Of View (commonly referring to porn)
Pr0n geek: Obfuscated spelling for porn.
PWN Own/Compromise/Take Over (by hacking) (usually a computer system)
RBTL Read Between The Lines
ROFL Rolling On Floor Laughing
ROFLMAO Rolling On Floor Laughing My Ass Off
ROFLMBO Rolling On Floor Laughing My Balls Off
ROTFL Rolling On The Floor Laughing
ROTFLMAO Rolling On the Floor Laughing My Ass Off
ROTFLMBO Rolling On The Floor Laughing My Balls Off
RTFM Read The Fine/Effing Manual
RTM Read The Manual
RTO Return To Owner
Screenie Screenshot
SFF So Effin' Funny
Skiddie/Skid geek: Script Kiddie
SMC / SMD (Very Offensive)
SMH Shake/Shaking My Head
SoB Son of a *&$%# (Curse)
STBM / S2BM Sucks To Be Me
STBU / STBY / S2BU / S2BY Sucks To Be You/Ya
STFD Shut The Front/Effing Door
STFD Sit The Eff Down
STFU Shut The Eff Up
STHD Sit The Hell Down
STHU Shut The Hell Up
STR8 Straight
SWAK Sealed/Sent With A Kiss
SYFM Shut Your Effing Mouth
t/y Thank You
TANSTAAFL There Ain't No Such Thing As A Free Lunch.  Pronounced tans toffle.

More than often used by geeks or scientists, in reference to the phenomenon (in life) where (often overwhelming, or even noticeable) sacrificies have to be made in the process of implementing or bettering a task or concept.
TBH / 2BH To Be Honest
THX Thanks
TLC Tender Loving Care
TMA Too Much Alcohol
TMI Too Much Info/Too Many Idiots
TMD Too Much Drugs/Driving/Drinking/(Many)Drinks/...
TMOT Taking My Own Time
TMP Too Many People, Too Many Parties, Too Much Partying
TMS Too Much Sex/Sun/...
TTYL (I'll) Talk To You Later
TYL Text You Later
TYVM Thank You Very Much
UL Upload (file to the internet)
UU / U-U / UnU Up And Up
WB / w/b Welcome Back
WIKI geek: What I Know Is
WOC Went Out Camping (original)
WOF Went Out Fishing (original)
WOH Went Out Hiking (original)
WOS Went Out Shopping/Skiing/Smoking/... (original)
WPoC Worthless Piece Of Crap (Swear)
WPoS Worthless Piece Of $&%* (Swear)
WTMA Way Too Much Alcohol
WTF What/Where/Who/Why The $&%*
WTH What/Where/Who/Why The Hell
WTMI Way Too Much Info, Way Too Many Idiots
WTMD Way Too Much Drugs/Driving/Drinking/(Many)Drinks/...
WTMP Way Too Many People, Way Too Many Parties, Way Too Much Partying
WTMS Way Too Much Sex/Sun/...
WYT Wait Your Turn
WYWH Wish/Wishing You Were Here
XO, XOXO Hugs & Kisses
XX, XXX Kisses
y/w You're Welcome