PeerProject is a versatile peer-to-peer filesharing client and file manager. It's intuitive and aesthetic while supporting many networks and features, including BitTorrent, G2, Gnutella, eDonkey, DC++, IRC, HTTP/FTP, and more. It's a mainstream fork of Shareaza p2p, for Windows and WINE.
aria2 is a utility for downloading files. The supported protocols are HTTP(S), FTP, BitTorrent, and Metalink. It has a powerful segmented downloading ability, downloading a file from multiple sources and multiple protocols and utilizing your download bandwidth to the maximum. It supports downloading a file from HTTP(S)/FTP and BitTorrent at the same time, while the data downloaded from HTTP(S)/FTP is uploaded to the BitTorrent swarm. Using Metalink's chunk checksums, aria2 automatically validates chunks of data while downloading a file like BitTorrent.