Unfortunately, the dev refuses to opensource this and the Escargot rewrite. There's a FOSS AIM server[1], and apparently it supports ICQ, which is new from the last I saw it.
Yeah very annoying. They ask for donations constantly but are enjoying keeping everything for themselves.
Especially since the original Escargot server software was open source.
I have a lot of love and nostalgia for aim and AOL and think it would be a fun motivator to learn more programming with a project like that but not without sharing.