"Based on the _libpurple_ protocol library, Adium can connect you to any number of messaging accounts on any combination of supported messaging services (see further down for the list) and then chat with other people using those services." (Emphasis mine)
"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. (...)
Libpurple was previously named Libgaim. "
So yeah, Pidgin is an option, because neither Adium nor Pidgin speak IRC, libpurple does. The support should be ~the same~, of course depending on the version of the library used.
http://www.adium.im/about/ ->
"Based on the _libpurple_ protocol library, Adium can connect you to any number of messaging accounts on any combination of supported messaging services (see further down for the list) and then chat with other people using those services." (Emphasis mine)
http://trac.adium.im/wiki/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. (...)
Libpurple was previously named Libgaim. "
So yeah, Pidgin is an option, because neither Adium nor Pidgin speak IRC, libpurple does. The support should be ~the same~, of course depending on the version of the library used.
More info: http://developer.pidgin.im/wiki/WhatIsLibpurple