eMule is a file-sharing client which is based on the eDonkey2000 network, but offers more features than the standard eDonkey client, because it´s open source but under the restrictions of the GPL License.

eMule Features:

• Clients use several networks to create one reliable network. (ED2K, Source Exchange, Kad)
• eMule´s Queue and Credit system helps to ensure that everyone will get the file he wants by promoting those that upload back to the network.
• eMule is completely free. eMule is also completely free of any adware, spyware, ect.
• Each file checked for corruptions while downloading to ensure an error-free file.
• The eMules Intelligent Corruption Control helps to speed up the correction of corrupted parts.
• Auto priorities and source management allows you to start many downloads without having to monitor them.
• The Preview function allows you to look at your videos and archives before they are completed. For video previewing, the publisher recommends the Video Lan Client.
• The eMule features Web services and a Web server that allows you to have quick access to and from the Internet.
• You can create categories for your download to organize them.
• To find the file you want, eMule offers a wide range of search possibilities which include: Servers (local and global), Web-based (Jigle, and Filedonkey), and Kad (Still in Alpha).
• eMule also allows you to use very complex Boolean searches that make the searches much more flexible.
• With the messaging and friend system, you can send messages to other clients and add them as friends. In your friend list, you can always see if a friend is online.
• With the build in IRC client, you can chat with other downloaders and chatters around the globe.

What's New in version 0.49a:

• Major Kad protocol improvements, like kad obfuscation, better NAT handling, direct callbacks, flood protections, etc.
• Several changes to the message system to get rid of spammers (by Captchas) and stay in touch with friends with dynamic IPs
• Several GUI improvements like storing searches between eMule sessions, a searchfilter for shared files and easier access to the comment filter
• If extended controls are enabled (and if available) Kad search results show the amount of known unique publishers for a file in parentheses in the availability column (this isn't equal to sources, but it is a bit more trustworthy indicator how common a file is).
• Updated CxImage lib to the latest version (6.0), fixes some image processing vulnability (low risk for eMule) [reported: Steve Manzuik/Juniper Networks]
• Fixed Unicode issue in stored and loading searches
• DirectCallback sources are now properly added to and checked against the deadsource list
• And as always fixing bugs and adding other small changes