qBittorrent 3.1.11

The qBittorrent project aims to provide a Free Software alternative to µtorrent. qBittorrent is an advanced and multi-platform BitTorrent client with a nice Qt4 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 project needs help on Windows front: qBittorrent was downloaded 145 000 times last month on Sourceforge and almost 80 percent of those downloads are for Windows. 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 v3.1.11 changelog:

FEATURE: Allow relative torrent paths when qBittorrent is already running (pmzqla)
FEATURE: Make Windows icons suitable for high dpi screens (pmzqla)
FEATURE: Increase maximum size of system icons (pmzqla)
BUGFIX: Fix crash in the "Content" widget when user would right click in it without a torrent selected (Ivan Sorokin)
BUGFIX: Don't show multiple unlock UI dialogs. Closes #2040. (sledgehammer999)
SEARCH: Fix bug where python would falsely be detected and nothing worked (paolo-sz)
SEARCH: Fix TorrentReactor search plugin (Bruno Barbieri)
SEARCH: Fix search engine encoding issues with python3 on Windows (Bruno Barbieri)
SEARCH: Pirate bay search engine update (DoumanAsh)
SEARCH: Internal improvements in the python code (Bruno Barbieri)
WINDOWS: Fix magnet link association. Closes #1952. (sledgehammer999)
WINDOWS and OSX: Fix again the program updater. The url was changed by sourceforge.net. Closes #1954. (sledgehammer999)
OSX: Fix compilation (sledgehammer999)
WEBUI: Set correct HTTP Content-Type in case of forbidden access. (pmzqla)
COSMETIC: Remove unneeded tooltip (pmzqla)
COSMETIC: Don't stretch the last section in the transfer list (pmzqla)
COSMETIC: Set minimum width of the left panel in the preferences (pmzqla)
OTHER: Optimize sorting of rows. This should have less CPU impact when many torrents are present. (Ivan Sorokin)
OTHER: Use the correct character encoding for exceptions coming from libtorrent. (sledgehammer999)
OTHER: Use boost:bind() as the docs show. Allows compilation with older gcc versions. (sledgehammer999)