Latetst version 0.5.1
MUTE protects your privacy by avoiding direct connections with your sharing partners in the network. Most other file sharing programs use direct connections to download or upload, making your identity available to spies from the RIAA and other unscrupulous organizations.
More info see: http://mute-net.sourceforge.net/howPrivacy.shtml
If your torrent client allows it you can choose which version you want to download, so the windows version the mac or the unix. There is also a windows only version(MFC MUTE). I have MUTE running on windows vista 64bit so I assume it will run on all windows versions perfectly!