Distinguish between Mac/Windows.

I think a HUGE improvement that could be made is the ability to search Mac related software or file formats, and the ability to simply filter out the windows formats. Users waste tons of time pawing through each file to figure out what they need, or if it is actually for windows, or mac, and half the time they have to download it just to figure out. I look forward to hearing what ideas you have prepared on this subject already.

[Lord of the Rings]

Common knowledge goes a long way here. I mean zip, rar, exe, cue, etc. are plainly windows formats. SIT, img & dmg are obviously mac formats.
The only time confusion arises is where some people may zip mac files in order to safely transport them across a windows network. But they will normally have in brackets (for mac.)