In the 1980s, Wayne Pearson was reportedly the first person to have used LOL while responding to a friend's joke in a pre-Internet digital chat room called Viewline. The Oxford English Dictionary first listed LOL in March 2011. These initialisms are controversial, and several authors recommend against their use, either in general or in specific contexts such as business communications. The list of acronyms 'grows by the month' (said Peter Hershock in 2003), and they are collected along with emoticons and smileys into folk dictionaries that are circulated informally amongst users of Usenet, IRC, and other forms of (textual) computer-mediated communication. It is one of many initialisms for expressing bodily reactions, in particular laughter, as text, including initialisms for more emphatic expressions of laughter such as LMAO ('laughing my ass off') and ROFL or ROTFL ('rolling on the floor laughing'). It was first used almost exclusively on Usenet, but has since become widespread in other forms of computer-mediated communication and even face-to-face communication. LOL, or lol, is an initialism for laughing out loud and a popular element of Internet slang.

Use of 'lol' in response to a joke, in a 2007 conversation on IRC

What does lmao mean