Zultrax www.zultrax.com

Easily runs all day long without bothering your work on your PC.
Comes totally clean with no adware, spyware or other unwanted extras.

It supports two networks amongst which Gnutella on which it behaves as a fair client. Zultrax does not block off other clients, does not post selfisly a lot of queries and replies fairly to queries of other nodes.