Shareaza
Shareaza is a Windows-based [multi] Peer-to-Peer client which supports the Gnutella, Gnutella2, eDonkey2000 & BitTorrent network protocols, developed by Michael Stokes.In late 2002, Shareaza's founder introduced Gnutella2, a reworked version of Gnutella with many fundamental updates to the protocol, and added support for it to Shareaza. This drew a lot of criticism from other Gnutella developers, because Gnutella2 was developed without any outside help or conferral. However, the Gnutella2 network has been doing well so far despite the fact that it was developed privately and was only supported by Shareaza. (The protocol is now supported by MLDonkey, Adagio, Gnucleus, and Morpheus) Opponents to the name of Gnutella2 refer to it as Mike's Protocol, or MP for short.
There are arguments that Shareazas Gnutella implementation is buggy and effectively harms the Gnutella Network, but to the day (april '04) no action has been taken on that account.