Forkk
This does sound like a really nice feature to have, but given the way groups are currently implemented, this could require a lot of redesigning.
Code from CENSORED will not be merged here without a signed agreement from the author agreeing to re-license it from GPL to Apache v2.
Looks like this got buried, but it definitely seems worth fixing. Labelled.
Known bug, working on fixing it.
I'll have a look when I get the chance.
MCNostalgia integration is a planned feature.
Auto-detection on windows is not very intelligent at the moment. I'll try to improve it when I get the chance.
I'll try to make mod installs more "intelligent".
Unfortunately I don't think that DotNetZip supports rar files. This issue will remain open though and may be implemented eventually.