Shareaza

Shareaza is a luxurious and sophisticated file sharing system application. It can harness the power of up to four separate Peer-2-Peer (P2P) networks, including EDonkey2000, Gnutella, BitTorrent and Shareaza's native network, Gnutella2 (G2).

Not only that, but Shareaza is completely free (as in beer, that is, source code is NOT available) and won't show any annoying ads or pop-ups. It won't install any unwanted third party programs that can wreak havoc with your computer. No spyware, no registration, no "paid version". Just download and use. Simple.

More over, Shareaza supports only Windows (32 bits) platforms.