aMule

amule.png

aMule is a peer-to-peer file sharing application, designed to connect
to the eDonkey and Kad networks. It has a wide range of features,
including many of the original eMule client, like:

* online signature, source exchange, compressed transfers, secure
identification, and IP filter support
* boolean search, which can be local, global, or in the Kad network
* checks against aggressive clients
* slot allocation, to decide the number of remote clients
* systray works well both in GNOME and KDE
* translations to many languages

Similar applications: 
eMule