qBittorrent - Lightweight and open source torrent client that runs on all major platforms.
Deluge - Deluge is a full-featured BitTorrent client for Linux, Unix and Windows.
µTorrent - Looking for a torrent site to download movies, music and more? Choose from top torrent sites like The Pirate Bay, RARBG, 1337X, and dozens more. (October 2019)
rTorrent - rtorrent is a BitTorrent client for ncurses, using the libtorrent library.
BitTorrent - BitTorrent is a peer-to-peer program developed by Bram Cohen and BitTorrent, Inc.
PicoTorrent - PicoTorrent is designed to be a tiny, easy-to-use BitTorrent client with low memory usage.