When I expand the tar.bz2 archive, all I got is a folder full of source files (I guess).
There is an AMule.app with a "no access" sign: it's a mere 504KB compared to the 45 MB of the 2.2.2 release, and of course it doesn't run at all.

I guess this is a folder for developers/advanced users who know how to install this stuff properly, but it should be explained better for dumb users as me.

Thanks in advance to anyone who brings better infos.