The ktorrent library is a c++ / qt 4 / kde platform based implementation of the bittorrent protocol (mostly client side).

the library supports connectivity to http and udp trackers, mainline dht and the new generation micro transport protocol (utp). in addition, it provides many powerful bittorrent network features including but not limited to torrent downloading and seeding, torrent creation and downloaded data verification, magnet links, advanced peer management, ip blocking lists.