icq

AQQ is a Polish (but available in English) multiprotocol instant messenger with support of: AQQ, Jabber, Gadu-Gadu, Tlen and ICQ. It has many great features like: one tabbed message window for all conversations; quick search for contacts; file sending (even through FTP thanks to...

Empathy is a messaging program which supports text, voice, video chat, and file transfers over many different protocols. You can tell it about your accounts on all those services and do all your chatting within one application.

Trillian is an instant messaging app that works on phones, tablets, and desktops while keeping your chats neatly synchronized between all of them! We think conversation should be easily shared between all of your devices, not trapped as text messages on your phone.