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.

This requires libsigc++ (libsigcxx in the SlackBuilds.org repository).