Unix

Morpheus
http://www.musiccity.com
Morpheus is a full-featured P2P file-sharing application that allows users to search for all types of digital media across the MusicCity Network.

Blubster
http://www.blubster.com
Blubster is a peer to peer network with a new private protocol that works without a central server.

WinMX
http://www.winmx.com
WinMX is a FREE file-sharing program like no other. It allows you to simultaneously connect to many established networks based on the OpenNap and Napster protocols.

Swaptor
http://www.swaptor.com
Swaptor is a tool to share all kinds of files. It has it's own network and offers nice community functionalities

Flipr
http://www.flipr.com
FLIPR is peer-to-peer file-sharing software that provides quality digital music files while accurately compensating copyright holders.

Omni
http://www.emphatech.com/index.html
Omni is a searchtool that uses aim, icq, msn, yahoo, napster AND gnutella, all in one program!

Swapnut
http://www.swapnut.com/
SwapNut's advanced features include upload limits, an extensive and well-established filesharing network and cross-platform compatibility, a feature the other leading networks don't even offer.

Filemaze
http://www.filemaze.com
FileMaze Direct Downloads is a free file sharing network.

Grokster
http://www.grokster.com/
Grokster is the latest generation of file sharing software.

File Leech
http://www.spectrumwebstudio.com/FileLeech/
The purpose of File Leech is to swap files, using a secured method and without using blind links, advertisements, or the hassle of going to a million web sites just for one thing.