First I didn't quite catch what people said using these abbreviations like LOL, ROTFL, BBL, etc..The Wikipedia came to my rescue though. The analysis there was amazingly terrific so that I got to learn several other expressions. Listed below:
LOL (also written with some or all letters lowercase, most commonly as lol or LoL) is a common element of Internet slang used historically on Usenet but now widespread in other forms of computer-mediated communication, and even face-to-face communication. It is an abbreviation for "laughing out loud"[1][2] or "laugh out loud".[3] LOL is one of many initialisms for expressing bodily reactions, in particular laughter, as text, including initialisms such as ROTFL ("roll(ing) on the floor laughing"),[4][5] a more emphatic expressions of laughter, and BWL ("bursting with laughter"), above which there is "no greater compliment" according to technology columnist Larry Magid.[6] Other unrelated expansions include the less common "lots of luck" or "lots of love".[7]
Besides, the Chinese cyber searching engines were also not bad. I got the following English abbreviations frequently used on internet and their equivalents in Chinese:
BTW：By the way，顺便说一句。
BRB：Be right back，马上回来。
TTYL：Talk to you later，回头再谈。
BBL：Be back later，过会儿就回。
kick your ass：打你屁屁。
PPL：people，人们。
PLZ：please，请，也有缩写成PLS。
RUOK：Are you OK?
IOWAN2BWU：I only want to be with you。
M$ULKeCraZ：Miss you like crazy。
CUL8R：see you later。
IMHO：In my humble opinion
IMHO, it's nice to learn those above.
