Gnugadu2 is a modular instant messenger written with GTK+ targeted
mainly at Polish users of propietary Gadu-Gadu network.

GnuGadu2 sports a plugin extensible architecture. Beside Gadu-Gadu
it also supports Jabber, Tlen.pl, sending smses to Polish mobile 
phones, spell checking, works with several sound servers.

WWW: http://www.gnugadu.org