Adium

Libpurple

Libpurple is the library which provides network-level connectivity for most services in Adium. Like Adium itself, it is licensed under the GPL. In addition to Adium, libpurple is the core of the Linux and Windows IM clients Pidgin and Finch. It is described further by a page in the Pidgin wiki.

Libpurple was previously called Libgaim.