@uncharted:
This is amiga.org, windows and mac posts should happen very infrequently. On the other hand there are lots of MOS and AROS posts, so it does seem unfair to just lump them all under "alternative" (especially since there's so few alternatives - it's not like we're talking Linux distros).
My suggestion is to keep "alternative" for the odd time that some regular needs help getting his USB camera to work with his PC, and add 3 new categories: "Pegasos/MorphOS", "AROS" (once these guys get huge, we might want to add a couple more categories for them) and "Emulators" (for WinUAE, etc). I think that should keep everything nicely categorized, and make it easier to find stuff you're particularly interested about.
You're probably right about the trolling though - I doubt anything other than strong moderation will solve that.