(Open Source) Business Object Servers

I have been developing in eMatrix (www.matrixone.com) for the last
three years and i've been amazed how quick I can build an application
that would take me 3 times the effort if I had to worry about RDBMS
work and OO language development (no offence to RDBMS developers).

eMatrix's base design using STEP where there are objects, attributes,
relationships, policies (governing lifecycle and access), groups,
roles... is an extremely powerful framework that has a life outside
of it's PDM roots. Although it does require quite a bit of horsepower
to run, I can see such systems to be the future of large client-server
application development.

For example, we pulled together a HR Performance and Development
system in a fraction of the time that an outside vendor was able to
make. And our system has many less problems.

Does anybody know of an Open Source project for a Business Object
Server sit above an RDBMS layer such as mySQL? We have people in
corporate who would love to see us have a less expensive alternative /
extension to eMatrix. Also, I would love to get involved with such a
project.

Thanks for your time and info :]

Timothy JavaDude Quinn