The qBittorrent project aims to provide a Free Software alternative to µtorrent. qBittorrent is an advanced and multi-platform BitTorrent client with a nice user interface as well as a Web UI for remote control and an integrated search engine. qBittorrent aims to meet the needs of most users while using as little CPU and memory as possible. qBittorrent is a truly Open Source project, and as such, anyone can and should contribute to it.

qBittorrent features:

• Polished µTorrent-like User Interface
• Well-integrated and extensible Search Engine
• Simultaneous search in most famous BitTorrent search sites
• Per-category-specific search requests (e.g. Books, Music, Movies)
• All Bittorrent extensions
• DHT, Peer Exchange, Full encryption, Magnet/BitComet URIs, ...
• Remote control through a Web user interface
• Nearly identical to the regular UI, all in Ajax
• Advanced control over trackers, peers and torrents
• Torrents queueing and prioritizing
• Torrent content selection and prioritizing
• UPnP / NAT-PMP port forwarding support
• Available in ~25 languages (Unicode support)
• Torrent creation tool
• Advanced RSS support with download filters (inc. regex)
• Bandwidth scheduler
• IP Filtering (eMule and PeerGuardian compatible)
• IPv6 compliant
• Available on most platforms: Linux, Mac OS X, Windows, OS/2, FreeBSD

qBittorrent 4.0.2 release notes:

• This is a hotfix release too. It addresses some important RSS issues. macOS builds will follow.
• NOTICE: If you find your torrents being paused instead of seeding, then right click on your torrent, choose Limit shario ratio... and adjust the setting.

qBittorrent 4.0.2 changelog:

• BUGFIX: Fix crash on some systems when creating address object for 255.255.255.255. Closes #7735. (sledgehammer999)
• PERFORMANCE: Change MixedModeAlgorithm default to TCP. This was the v3_3_x default and should sustain higher speeds. Closes #7779. (Chocobo1)
• PERFORMANCE: Stop logging IP filter parsing errors after a while, otherwise the GUI freezes or qBittorrent doesn't start. (sledgehammer999)
• GUI: Implement stable sort. Rows in transfer list shouldn't flicker anymore. (Chocobo1)
• WEBUI: Fix build when webui is disabled. (Heiko Becker)
• RSS: Fix build because of missing header. Closes #7805. (thoradia)
• RSS: Fix RSS parser. (glassez)
• RSS: Implement Import/Export RSS rules in legacy(aka v3_3_x) format. (glassez)
• RSS: Implement Import/Export RSS rules in JSON format. (glassez)
• WINDOWS: Fixed blurry text under Windows by setting DPI awareness to default. (TheNicker)
• LINUX: Fix i386 build. (Evgeny Lensky)

Download: qBittorrent 4.0.2 (32-bit) | 17.9 MB (Open Source)
Download: qBittorrent 4.0.2 (64-bit) | 21.1 MB
View: qBittorrent Home page

It will take sometime for the trackers to add this to the client whitelist. Don't update the torrent client until that happens.