BearShare 6 is actually iMesh in disguise, and it uses their own proprietary network.
BearFlix is a crippled video-only form of BearShare but it still uses the gnutella network.
The beta is the original form of BearShare and it can download anything.

The trial period is irrelevant because BearStart changes the date for you when
you use it to start BearShare then changes it back even before you see
BearShare open up.