Limewire-gnutella based, you'll see users from all the gnutella programs with files. And no secret tracking stuff like is present in bearshare.
Morpheus.
I use both, what I can't get from one I usually find with the other.
I have an older version of bearshare but could not get it to work on another pc thru ics. It's ok, except for the nag to update so they can track you.