IRC Clients for Other Operating Systems

This is a catch-all for desktop operating systems other than Windows, Mac OS X, and Linux/Unix,

Haiku

Vision is a native BeOS/Haiku IRC client.

In addition, a number of the Unix clients, such as irssi have been ported to Haiku.

MS-DOS

The mTCP suite of applications includes IRCjr, a basic IRC client for MS-DOS systems, which can even run within DOSBox.