The main idea of P2P technology is that users pool resources together and create a social service. Because users donate resources, there is no cost to the content distribution infrastructure. In the UK, the BBC a file-sharing system for TV program downloads. The largest encyclopedia on earth, Wikipedia was solely created by volunteers without authoritative, central editors. The Skype VOIP telephony software uses P2P to reduce the cost of Internet telephony and became a market leader in just a few months. P2P is now the 'killer app' of the Internet.
Torrent Swapper is an open sourced sociable peer to peer file-sharing client based on the Bittorrent protocol that is ideal for high-speed distribution of large files that has a basic understanding of human friendships, of user tastes in content, and of Internet connectivity between users. Torrent Swapper supports simultaneous downloads, download queue, selected downloads in torrent package, fast-resume, disk cache, speed limits, port mapping, proxy, and ip-filter.