I'm wondering about something which might have high document storage requirements. I guess it would have to be web-based (don't know how exactly one would integrate arc with another GUI environment).
I know I've seen comments here about integrating it with a db. Anyone remember the article # or URL?
Option 4. Get the FFI working to access MySql and other more traditional database systems.
Some people had been working on the FFI interface, but so far I've yet to see anything that works. You can read my noob entry about this here: http://arclanguage.com/item?id=10839 and there were recent attempts by others as well.