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.
Empathy uses Telepathy for protocol support and has a user interface based on Gossip. Empathy is the default chat client in current versions of GNOME, making it easier for other GNOME applications to integrate collaboration functionality using Telepathy. More Info »
Multi-protocol: Google Talk (Jabber/XMPP), MSN, IRC, Salut, AIM, Facebook, Yahoo!, Gadu Gadu, Groupwise, ICQ and QQ. (Supported protocols depend on installed Telepathy Connection Manager components.) Supports all protocols supported by Pidgin.
File transfer for XMPP, and local networks.
Voice and video call using SIP, XMPP and Google Talk.
Some IRC support.
For detailed list of supported protocol features see here
Conversation theming (see list of supported Adium themes).
Sharing and viewing location information.
Private and group chat (with smileys and spell checking).
Automatic away and extended away presence.
Automatic reconnection using Network Manager.
Python bindings for libempathy and libempathy-gtk
Support for collaborative applications (“tubes”).