X-Chat, commonly written XChat or xchat, is one of the most popular IRC clients for Unix-like systems. It is also available for Microsoft Windows and Mac OS X (via an offshoot of the project, called X-Chat Aqua, which keeps in sync with the main development branch and is much more popular than the official version maintained by the Fink project).

XChat has a choice of a tabbed or tree interface, support for multiple servers, and a high level of configurability. Both command line and graphical versions are available, although use of the graphical version far outweighs use of the command line version.