Thank you kindly, MCortez, for a patch that:

Added is a patch that adds a rough Groups implementation. This patch allows 
the creation, adding and maintaining Groups, Roles and Members. Work has begun 
on a very naive implementation of messaging, and minimal support for notifications 
{no attachments yet}. Proposals are not yet supported, but are on the to-do list.
This implementation is not active by default, and must be configured in 
OpenSim.ini to become active.

1 files changed, 14 insertions, 0 deletions

diff --git a/OpenSim/Region/OptionalModules/Resources/OptionalModules.addin.xml b/OpenSim/Region/OptionalModules/Resources/OptionalModules.addin.xml
new file mode 100644
index 0000000..4795edc
--- /dev/null
+++ b/OpenSim/Region/OptionalModules/Resources/OptionalModules.addin.xml
@@ -0,0 +1,14 @@
+<Addin id="OpenSim.Region.OptionalModules" version="0.1">

+    <Runtime>

+        <Import assembly="OpenSim.Region.OptionalModules.dll"/>

+    </Runtime>

+

+    <Dependencies>

+        <Addin id="OpenSim" version="0.5" />

+    </Dependencies>

+

+    <Extension path = "/OpenSim/RegionModules">

+      <RegionModule id="XmlRpcGroups"          type="OpenSim.Region.OptionalModules.Avatar.XmlRpcGroups.XmlRpcGroupsModule" />

+      <RegionModule id="XmlRpcGroupsMessaging" type="OpenSim.Region.OptionalModules.Avatar.XmlRpcGroups.XmlRpcGroupsMessaging" />

+    </Extension>

+</Addin>