THX may refer to any of the following:
1. A system of standards developed and founded by Tomlinson Holman, a creative director for George Lucas in 1983 to get the highest quality of sound in home theater systems and computer games. The name THX comes from two sources. One is the name of Lucas' first film, THX 1138. The other is short for 'Tom Holman Xperimental'.
2. Shorthand for thanks, THX is commonly used in chat rooms and text-based communications. TNX is also sometimes used for saying thanks. Below is an example of how this could be used in chat.
User1: That's pretty funny.
User2: Heh yeah, AFK.
User2: Ok I'm back.