Hi Jon!
I recently became aware of your project. Is GPC currently being developed? Are Delphi classes and exceptions going to become a reality anytime soon? I wouldn't mind working with some pre-stable code if they are. If they aren't what are the GPC alternatives?
GPC is being developed, alive and well. :-) Delphi classes have been planned for quite a while now, but I don't know to what point they are implemented so far. However, GPC has Borland-Pascal style objects with a few extensions.
As for exceptions, I'm currently working on a standard class library for GPC that provides, among other things, exception handling. It is work in progress, without documentation etc., but I hope my demo sources are readable enough to give you a start. You can download the library from http://www.markus.gerwinski.de/gnualp/.
Of course I wasn't able to implement a real try..except syntax in my units, but I tried to make my API functions look as close as possible. If you give it a shot, let me know how it's going. :-)
Regards,
Markus