Eoin O'Callaghan - 44KB (Open Source)
Halite is a free BitTorrent client that is based upon the popular libtorrent library. Halite has been developed in C++ and relies on portable C++ source libraries called Boost libraries to operate efficiently.
Halite is a simple, yet useful BitTorrent client that has a low memory footprint, a clean interface and is easy to use. It has lots of features such as file selection and/or file priority specifications, a managed torrent queue system, disk cache support, support for Magnet URI torrents, and super-seeding. It also has the ability to edit trackers specified in the torrent, and it has the ability to create torrent files. What more could you need?
*Note: Starting with version 0.4.0.1, Halite no longer runs on Windows XP.