Xirc
- Fully featured cocoa IRC client.
- http://xoomer.alice.it/gluca.cannata/

MacOSX.com Chat Client
- Customized IRC client to connect to the IRC channel created for the MacOSX.com website.
- https://sourceforge.net/projects/macosxchat/

ShadowIRC
- Mac-only GPL IRC client.
- http://www.shadowirc.com/

Conversation
- Client developed with ease of use in mind. Versions for 10.2 and 10.3 available. Documentation, downloads and feature list. Donationware.
- http://homepage.mac.com/philrobin/conversation/

SourceForge.net: Project Info - MChat
- Customized IRC app for the #macintosh channel on freenode.net.
- http://sourceforge.net/projects/m-chat/

MacIrssi
- Based on the *nix IRC client irssi. Free, open source.
- http://www.g1m0.se/macirssi/

Irssix
- A free (GPL) IRC client for Mac OS X based on the UNIX client Irssi.
- http://gizmolabs.org/~andrew/andrewweb/project.php?pid=2&tab=0

ChiperSoft Systems - Minerva
- Formerly called AthenaIRC. Shareware. Origins and history of the program, feature list with screenshots, downloads, and support forums.
- http://www.chipersoft.com/minerva/

X-Chat Aqua
- The Mac OS X sister of the Unix program XChat.
- http://xchataqua.sourceforge.net/

Snak
- Client for MacOS 9 and up. Advanced features including ircII scripting support and parental control.
- http://www.snak.com/

iRC
- Native Mac OS X IRC client [Shareware].
- http://www.mice-software.com/products.php?product=7

Ircle
- IRC client for MacOS.
- http://www.ircle.com/

Colloquy
- An IRC client for Macintosh OS X. Contains screenshots, documentation, support and download area.
- http://colloquy.info/