Is still http://freedownloadmanager.org/ the official site?
If so, there is uploaded there, the 3.9.3 build 1360 version, that's stating FDM as open sourced (and prompts for code download here), while here there is an older version (3.8.1173).
Is the code, still open?
If so, where can someone get it?
Oh! I think I found it! :-)
Seems like, FDM is at SVN now.
OK! Please ignore this post.
Maybe the official site needs some clarification here, in order to be more obvious.