1. Miranda : a modular system. It supports ICQ, MSN, Yahoo, IRC, Jabber. Journal Discussion
  2. Pidgin (formerly Gaim) : compatible with AIM (Oscar and TOC), ICQ, MSN Messenger, Yahoo, IRC, Jabber, Gadu-Gadu and Zephyr
  3. aMSN : MSN Messenger clone
  4. Trillian : supports AIM, ICQ, MSN, Yahoo.
  5. VIRC : IRC client
  6. Kvirc : IRC client