eMule is a new filesharing client which is based on the eDonkey2000 network, but offers more features than the standard eDonkey client, because it's opensource but under the restrictions of the GPL License.
With eMule you can download video ( divx ), music ( mp3 ), etc.|
eMule has a feature called "The credit system". It is used to reward users contributing to the network, i.e. uploading to other clients. The strict queue system in eMule is based on the waiting time a user has spent in the queue. The credit system provides a major modifier to this waiting time by taking the upload and download between the two clients into consideration. The more a user uploads to a client the faster he advances in this client's queue.