LimeWire P2P

It is a peer-to-peer file sharing program.
I guess you know how it works. If not, this is what the publishers say:


LimeWire is a peer-to-peer file sharing program that connects to the Gnutella network and enables users to search for and download files from other users. It is not a web site or a service, and LimeWire does not provide any of the content found on the network. LimeWire enables you to share your files with millions of other LimeWire users, and vice versa, so there is always a diverse selection of files available.

Get it here:  http://www.limewire.com/download