There are some good programs:
- OpenChat (use the GemZ addition!)
- GTIRC from Gammatech
- PMBitchX is a port of the Unix-software BitchX. Highly customizable. The last version I tried came with too much predefined kiddies stuff (lots of bans, kicks and silly statements)
- VIRC works, but development has stopped in alpha state
- Xchat needs XFree86/OS2, but is the best chat client for any OS. Period. If you want to give it a try mail Platon Fomichev (firstname.lastname@example.org) for the latest version (1.8).