LibTorrent is a BitTorrent library written in C++ for Unix. It is designed to avoid the redundant buffers and data copying that most other BitTorrent implementations suffer from. The library is single-threaded and the client handles the select loop. An interactive ncurses client is included as an example.

libtorrent is a C++ implementation of the BitTorrent protocol with the goals of being efficient and easy to use.

It is written in and has its main library interface in C++. Its most notable features are support for Mainline DHT, IPv6, HTTP seeds and μTorrent's peer exchange.