qBittorrent is the closest open source (GNU GPL v2 license) equivalent
to uTorrent.  It is based on the Qt4 toolkit and libtorrent-rasterbar.

Features:

	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 URI, uTP
	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)
	uTorrent spoofing to bypass private trackers whitelisting
	Advanced RSS support with download filters (inc. regex)
	IP Filtering (eMule and PeerGuardian compatible)

WWW: http://www.qbittorrent.org/