Grouparchy (README) uses objects in context to represent structure and relationships of individuals. Objects representing the application specific context of members are grouparchy contexts (README). Objects representing individuals within contexts are grouparchy members (README). Contexts, members, and groups all have types which are interfaces specialized using grouparchy.schema.
This framework provides powerful group semantics and multiple
ways to attach behavior to those groups. The clearest example of such behavior is local roles based upon those groups, provided by grouparchy.pas.localrole.
Grouparchy was written to support the social networking and group semantics required for The Groupery. It is about 90% through a version 2 that addresses all of the problems discovered with the first version. All that is left is to port over the UI and other top layer code. I'd very much like to finish this and start promoting it if I ever have any free time or if anyone wants to sponsor it.