Are there any projects interested in object functionality? (+ rule bases)

Dear all,

for the sake academic teaching, a colleague asked me in how far PostgreSQL does support object functionality these days.

I am afraid my web research was not very fruitful to him; the impression is that hardly anybody is occupied in working on PostgreSQL object functionality -- have ORM mappers grown so strong?

The docs report that the SQL/OLB ISO/IEC 9075-10 part of the SQL standard have no implementation yet.

So I'd like to place my questions here:

* are there any people / projects known which are interested in ORDBMS / OODBMS usage of PostgreSQL? Strict SQL standard conformance is less important than the possibility to provide instructive and impressive examples to students.

* are there any people / projects known which are interested in extending PostgreSQL at a higher level (plpgsql, creating operators, etc.) for the sake of ORDBMS / OODBMS functionality?

* are there any people / projects known which are interested in extending PostgreSQL on the level of developing C code for the sake of ORDBMS / OODBMS functionality?

* in how far does the backend support such efforts -- would it do fine, or is rather to be expected that doing ORDBMS / OODBMS driven queries would lead to disastrous performance?

* are there any people / projects known which are interested in using the rule (?trigger?) system of PostgreSQL (maybe with extensions) to achieve some kind of rule base / datalog type inference engines? In how far does the backend constrain this in regard of performance?

Thanks a lot in advance,

    Nick