Welcome back, Jeff ... our copy of nsora is a good place to start. I know I fixed one bug in regard to the handling of LONG datatypes before we released OpenACS 4.5. LONG is deprecated (in favor of BLOB) but is still used in a lot of Oracle's internal tables, such as those interrogated by the OpenACS schema browser. Somewhere along the path from Oracle 7.x to Oracle 8.1.6 the handling of LONG by the Oracle client library got munged and a driver dependence on documented behavior caused segtraps ...
Put me down as a committer for nspostgres.so ("dhogaza").
As far as whether or not the Windows stuff can be a bolt-on to the AOLserver tree ... you'll need to talk to the guy who's doing it, Jamie Rasmussen.
