Quazaa is a cross platform multi-network peer-to-peer (P2P) file-sharing client inspired by Shareaza which will support Gnutella2, Ares, eDonkey2000 (eMule), HTTP, FTP, and BitTorrent. Using the Qt software development kit.
The PeerProject is a versatile p2p filesharing client and file manager. Intuitive and aesthetic while supporting many networks. BitTorrent, Gnutella, Gnutella2 (G2), eDonkey, DC++, HTTP/FTP, IRC, and more. A mainstream dev fork of Shareaza. (Further development on Envy.)
Skulls is a Multi-Network WebCache used from P2P clients to bootstrap.
It support all versions of the GWC specification.
It is used mainly for Gnutella/Gnutella2 but it can work with any network (after configuring vars.php).
It use text files to store data so it doesn't require SQL.