Groups is a Zope product that adds Group support to Zope. Groups should work 
without Silva, but this independent support is very raw at the moment
(no user interface).

Note that the Groups product makes use of a rather dirty technique called 
monkey patching to add groups support to the Zope core. This may conflict
with other products which try to do the same. If this turns out to be the
case, it is safe to just remove the Groups directory from your Products
directory and restarting Zope.

