Not kind of "blah blah" to use a fake name, e-mail address, and web URL.
I haven't checked the website, but the superserver was supposed to go Open Source. Getting it ready is what supposedly prevented everything going Open Source six months ago.
InterBase supports stored procedures, but I don't know how easy it would be to port the PL/SQL routines to them. Postgres' PL/pgSQL was designed to be a poor-man's PL/SQL and because of this porting such functions has been surprisingly simple.
InterBase has outer joins, but only the SQL92 syntax (the right thing to do, abstractly, but less help for the ACS). So all outer joins need rewriting, but the task would be simpler than it is in Postgres.
There's no oracle-style "sequence", either, so key-generating and communicating code would need to change, that's kind of a pain.
Etc. A port would be a major effort, on about the same level as Postgres.
The good news is that ACS 4.0 should centralize a lot of the SQL porting effort, so supporting both InterBase and PG could in theory be more easily done with one code base. We'll see when it comes out.
