Object-Orientation FAQ

An object-oriented, distributed database programming language.  Its
most interesting feature is the presence of system-level version
control, which is used to support schema evolution, system-level
versioning (as a way of improving concurrency), and objects with their
own notion of history.  System consists of programming language (PAL)
and distributed persistent object manager. 

REFERENCES:
        Anders Bjornerstedt and Stefan Britts. "AVANCE: An
        Object Management System".  Proceedings of OOPSLA88.