Azureus

Download now
A popular torrent manager that allows you to install plug-in and tweak your own settings.If you're looking for a slew of features - then Azureus is for you.  It supports plug-ins, so what it doesn't have can be slapped on after the fact. It's built in Java, and  Azureus can run on any platform where Java can be installed. Built-in features include advanced bandwidth management, an embedded tracker, management of files within torrents, support for trackerless torrents and a connection optimizer that can traverse firewalls with ease.