Hi Patrick,
thanks for the pointer, sounds interesting, I'll check it out. However, it will probably take several months until we'll come up with something useful. We would integrate it with Project/Open (http://www.project-open.com/), which is already able to capture costs and invoices related to projects.
Did you check out SQL-Ledger already? It also runs on PostgreSQL, but using a Perl-based web interface.
Bests,
Frank
