A type of program used to connect to an IRC server, where you can chat with other people over the Internet in real time. There are many different IRC clients designed for use on different operating systems, some of the best being mIRC or Pirch for Windows, ircII or X-Chat for Unix, and ircle for Macintosh. There are also clients available for BeOS, OS/2, and Amiga, as well as most other major operating systems.