Gnutella
Gnutella is a file sharing network by Justin Frankel and Tom Pepper of Nullsoft in early 2000. After the Nullsoft acquisition by AOL the program was made available for download on Nullsoft's servers. But next day, AOL stopped the availability of the program over legal concerns.
The reverse engineered and compatible open-source clones began to appear few days after the AOL restrained Nullsoft's Gnutella project. Gnutella is now developed by .different groups. Gnutella does not refer to any one project or piece of software, but to the open protocol used by the various clients.
The Gnutella network is a fully distributed client based file sharing system. Gnutella is the third-most-popular file sharing network on the Internet, following eDonkey and FastTrack.