is a popular, open source P2P file sharing application. Besides the official free eMule download, an alternative eMule Plus client and other applications called "mods" are also free and widely used. Try these sites to find free eMule downloads:
eMule clients connect to the Overnet / eDonkey2K network. eMule free downloads are often very easy to install, have a user interface translated to many languages worldwide, and use and offer a good selection of files to download.