azureus

Azureus is a Java-based BitTorrent client, with support for I2P and Tor anonymous communication protocols. It is free software and cross-platform, and currently runs under Windows, Mac OS X, GNU/Linux and Unix. Azureus was first released in June 2003 at Sourceforge.net, mostly to experiment with the Standard Widget Toolkit from Eclipse. It is one of the most popular BitTorrent clients. ^[1]

GUI

Azureus allows users to download multiple files in a single graphical user interface (GUI). The program also features detailed statistics and a large number of user-configurable settings. While downloading a file, the user can view many different statistics including:

• Current download and upload speeds and estimated time remaining
• The percentage of each file completed and information on the "pieces" (small parts of the complete file) still needed including the piece number and availability
• File names, sizes and levels of completion for specific files within the download directory (BitTorrent allows a user to create a torrent file for an entire directory). It is also possible to prevent certain files from downloading.
• Peer data including IP addresses (and country with the use of a plugin), the speeds at which you are downloading and uploading to/from them, the port they are running BitTorrent on, and the BitTorrent client they are using
• The total and average "swarm speeds" [1]

Features

Azureus allows users to specify maximum upload and download speeds and is configurable like the many other clients. Azureus also allows users to open some files that have been completed before the entire torrent from within the program. Additionally, Azureus can serve as its own tracker, allowing users to share their own files with others without uploading it to any site. Azureus supports Message stream encryption, an anti-throttling method. Peer exchange and the magnet: URI scheme are supported. Azureus's functionality can be expanded via various plugins, one of the more popular being Country Locator. An integration with the Nodezilla Grid Network is implemented as a plugin, enabling the anonymous storage, sharing and publication of torrent files.

Logo

The program's logo is the Blue Poison Dart Frog (Dendrobates azureus), shown on the Azureus webpage, as well as within the program's start-up splash screen, which no doubt lent its name to the project. The name was given to the project by co-creator Tyler Pitchford, who uses the Latin names of Poison Dart Frogs as codenames for his development projects.

DHT

Azureus version 2.3.0.0 introduced the Distributed Database function (a form of DHT, namely Kademlia), which is an expansion of the BitTorrent protocol, making it more independent from trackers. This allows for a torrent where the original tracker is down or very slow to get peer data (and eventually download the files) from other peers that are using Azureus 2.3.0.0 or newer. The downside to this is private trackers, where membership is required, that do not want non-members downloading their torrents are required to alter their torrents so the Azureus client knows not to share peer information about that swarm. Some critics also say that this is simply "reinventing the wheel," referring to earlier peer-to-peer protocols and programs the weaknesses of which BitTorrent was praised for overcoming. Others see it as an evolution of the BitTorrent protocols. Azureus uses its own form of DHT incompatible with Bram Cohen's BitTorrent client.

Azureus was modified to create the Localhost Program, which uses the Distributed Database to maintain a virtual file system.

Criticism

Versions of Azureus before 2.4.0.0 were criticized by some for its use of CPU and memory resources. This was due, in part, to the program's reliance on the Java virtual machine. However, this issue has been rectified as of version 2.4.0.0. It is now possible to run Azureus using GCJ, thus performing as native code and considered fully free software as it no longer depends on a proprietary virtual machine.

See also

• BitTorrent
• Comparison of BitTorrent software

Notes

1. ^ Sourceforge Top Projects

External links

• Official website
• Azureus wiki
• Azureus project page on SourceForge
• Nodezilla plugin wiki
• The Beginner's Guide to Azureus
• A Complete Bittorrent Guide and Associated Tools
• Optimization for German DSL connections