more techno oriented first:

http://www.realaudio.ch/
http://www.textone.org/
http://www.acediamusic.org/
http://pathmusick.hermetech.net/
http://www.stadtgruenlabel.de/
http://www.d1recordings.com/banner_news/index.asp?id=7
http://www.sinergy-networks.com/
http://www.2063music.de/
http://www.epsilonlab.com/ (down atm but should be up soon)
http://www.peromusic.com/
http://www.archipel.cc/
http://www.fragmentmusic.net/
http://www.plainaudio.com/
http://www.exegene.com/
http://www.datamusik.dk/
http://www.notype.com/nishi/
http://www.8bitpeoples.com/