"LMS" can either refer to "Like My Status," "Last Man Standing" or "Laughing Myself Silly." The first is a request to show appreciation of an update in a social network, while the second refers to a style of a deathmatch game and the third to a general expression of laughter.
In social networking, for example on Facebook, people can post statuses that provide updates to their lives. Others are then permitted to like these statuses to either show agreement with the status or simply to provide a notification that they have read the status. In deathmatch games, players battle one another or wait it out until the last person survives or endures till the end of the challenge. This person is the last man standing.