Azureus is a java bittorrent client.
It provides a bittorrent protocol implementation using java language.

Azureus offers multiple torrent downloads, queuing/priority systems (on torrents and files), start/stop seeding options and instant access to numerous pieces of information about your torrents.
Azureus now features an embedded tracker easily set up and ready to use.

Screenshot

• Core | Show built-in plugins in config view
• Core | Fallback encoding for torrents (a-zA-Z0-9 type encoding with hex chars for others)
• Core | Numbers now localized to selected language
• Core | More "polite" hash checking...doesn't stress the cpu/system as much
• Core | Tracker seed retention limit added to limit tracker memory on torrents with high seed counts
• Core | Show Bad ips/banned ips in ipfilter window + allow clear/reset
• Core | Option to start torrents in a stopped state
• Core | Torrent removal rules. Initially to handle unauthorised torrents + AZ update torrents
• Dev | More features for torrent creation
• UI | New peer columns to help track leechers
• Plug | Experimental data upload facility for tracker web pages
• Plug | WebUI support for "host" operation
• Plug | Run the web interface standalone (outside of a browser)
• Plug | Option to keep hold of UPnP port mappings when closing Azureus

• Core | More sensible merging of plugin.properties on plugin update
• Core | Retuned tracker connect failure retry interval
• Core | Torrents downloaded by URL now named after torrent if not already .torrent
• Core | Performance of ipfilter checking improved
• Plug | Green colour used on tracker web pages now more legible

• Core | 99.X% / continuous hash fails fix
• Core | Basic plugin config model parameters not working in non-swt (e.g. console) mode
• Core | Fix for 'completed' announce event not being sent on occasion
• Core | Fix for occassional missing of resume data write -> recheck on start up
• Core | Bad peers not being detected on hashfail if they contributed all blocks
• Core | Better handling of "auto import" + default torrent save dir being the same
• Core | Strip resume data on open of new torrent
• UI | Fix bug where failed-hashcheck pieces never reappeared in Pieces view
• Plug | Web UI authentication for torrent download not working with default port URLs