David,

This is not difficult at all.

You own the source code. All your client has paid for so far is the application constructed from the source code -- not the source code itself. I usually explain it this way: If you buy a hand made Lamborghini outfitted to your specifications, you own no interest at all in the factory that made the car, the custom jigs required, the custom machinery that may have been necessary to make the parts of the car. You only own the car.

You client has paid for the application, not the custom source code that made the application.

I strongly suggest you do two things:

1. Read my UT article on Software Development Agreements located at http://www.levelextreme.com/VisualFoxPro/Articles/474.asp, and

2. Consult an attorney before you do anything at all.

My attorney alarms are going off all over the place based on what you stated in your post. As you suspect, there is something not quite right going on here.

I would not, under any circumstances, on this factual basis, turn over my source code.

If I did, I would want a whopping fee up-front, a participation in any resale that includes all or part of my code, logic, design or architecture, and control over inclusion of the design, architecture, logic, or code into any other application.

Talk to a lawyer, please.

Regards,