Link: http://www.slsknet.org

I casually found this software and network which really caught my attention.
I defend their free & open philosophy and hopefully networks like these will keep growing.

Soulseek is a file-sharing network and application created by Nir Arbel, a former Napster programmer.

Most of the music first found on Soulseek was/is underground electronic music or music created by the users themselves. To this day, Soulseek remains a source for avant-garde and underground independent music. Some artists without a label or who depend on word of mouth for the spread of their music use file sharing programs such as Soulseek to distribute their work.

more from wikipedia here

RULES:
Soulseek(tm) You should only share and download files which you are legally allowed to or have otherwise received permission to share. Soulseek(tm). was created to encourage the sharing of public domain music from unsigned, independent artists willing to share their work and communicate with a large audience in an efficient way.

more

Soulseek Software Download for all OS platforms
Official site ( for windows ) ( it can be emulated on Linux with Wine )

For Linux / Unix there are also some clients:

PySoulSeek @ http://www.sensi.org/~ak/pyslsk
Nicotine @ http://nicotine.thegraveyard.org/#download
Soulfind @ http://seeschloss.org/soulfind.html

For Iphone:
iSlsk @ http://www.errrick.com.ar

Keep it clean, open and free