dvicino/libtorrent
LibTorrent is a BitTorrent library written in C++ for *nix, with a focus on high performance and good code. The library differentiates itself from other implementations by transfering directly from file pages to the network stack. On high-bandwidth connections it is able to seed at 3 times the speed of the official client. The client uses ncurses and is ideal for use with screen or dtach. It supports saving of sessions and allows the user to add and remove torrents.