BearShare is up to version 10 now which sounds like the version you probably used. And yes, iMesh took over BearShare when it was sold.
If you wish to use the gnutella network instead, there are plenty of options. LimeWire (
pirate edition recommended),
FrostWire 4,
. Phex,
. GTK-Gnutella,
. ShareAza, and even the earlier version
BearShare 5.1 Beta which does run on gnutella network but has no junkware.