I guess there are two things that can be called Delphi in a Linux environment - an Object Pascal compiler, and Kylix Delphi-compatible libraries from Borland (please correct me if I'm wrong). If I'm not mistaken, Gnu and Free Pascal implement a rich subset of Object Pascal.
Would it be sufficient if some of these switches were enabled? We would really like to avoid use of tools which are non-free for commercial applications (like Kylix), unless they prove superior.