ircII (pronounced
i-r-c-two, and sometimes referred to as
IRC client, second edition) is a
free, open-source Unix IRC and
ICB client written in
C. Initially released in the late 1980s, it is the oldest IRC client still maintained. Several other UNIX IRC clients, including
BitchX, EPIC, and ScrollZ, were originally forks of ircII. For some, ircII set the standard of quality for IRC clients, however other clients have since overtaken ircII in terms of popularity. The application has been promoted as being "fast, stable, lightweight, portable, and easily backgrounded".