BitTorrent clients compared
BitTorrent is a very popular protocol for transferring larger files across the Internet. The protocol can be used in a true peer to peer fashion locating peers using DHT. In practice it's usually used with centralized trackers who keep track of who's sharing a file and what parts of it they have. The blocks that make up a given file is always transferred directly between peers in a "swarm" of users sharing a file. Many Linux distributions offer torrent downloads of their ISO install images to decrease bandwidth costs and lighten load on their servers.
BitTorrent is a controversial protocol since it, like all other protocols such as https and ftp, can be used to transfer files that are subject to copyright without the right-holders permission. The malware-peddler malwarebytes likes to place sites mentioning the existence of this protocol on blacklists.
Graphical BitTorrent Clients
qBittorrent is a very advanced and feature-rich BitTorrent client. It has built-in search (most others are lacking this important feature), a RSS feed reader with auto-downloading based on regular expressions and a headless mode for running it on servers & controlling it from a web browser.
|Transmission is a very user-friendly BitTorrent client with a clean and simple interface. It is available in Qt, GTK and CLI versions. Transmission does not have any extra advanced functionality. It has what you need to create, upload and download torrents and that's it. It is meant to be clean and friendly and it is.|
KTorrent is a simple and light BitTorrent client which gets the job done. KTorrent tries to be what Transmission is: easy to use with a clean interface. KTorrent does not quite get it right and it looks cluttered in comparison. KTorrents core functionality can be extended by plugins and there are many available. Most of them work but the "search" plugin does nothing but freeze it and make it run 1 core at 100% indefinitely.
|Vuze, formally known as azureus, is a popular client on Windows. It's written in Java and it it's slow and bloated compared to all the other BitTorrent clients available on GNU/Linux. It can be installed and used but it's not really a very good choice.|
- RTorrent is the obvious choice if you want a text-based BitTorrent client running in something like tmux or screen. It is very efficient and it is able to handle seeding of hundreds of torrents to thousands of peers just fine.