Q. Will my existing Paradox for DOS code work if I upgrade to say Paradox for Linux?
A. Absolutely not. You have to start pretty much completely over. Let's focus on moving from Paradox for DOS to Paradox for Windows because that's really what we're talking about. From Dos there was a complete paradigm shift from Paradox for DOS and there is pretty much NO upgrade path that works well. The tables, your data, moves over just fine. You can export querries but that's it. All your scripts, forms, and reports must be rewritten.
Q. Does WINE actually work?
A. Yes, it does. The Paradox 9 for Linux version doesn't support the application framework as well as a few Windows specific features, but pretty much all your Paradox for Windows code should run just fine. So, for running a Paradox for Windows application built in Paradox 9 for Windows will work fairly well if you didn't use the application framework. In preparation for writing the four chapters on Paradox for Linux for the book WordPerfect Office2000 for Linux, I tested over 3,000 very specific forms with some of the most advanced code I have in it. Nearly all worked well.