>Hmm. Cross platform support implies producing platform specific code -
>how do you do that other than with a code generator? And, without updates
>the framework can only support existing platforms.....

This is one of the reasons Visual FreePro is taking so long to develop. I have had to make design considerations which allow for variables at various points up front, that way in the future additional platforms can be ported to relatively easily. I have only one module that has a lot of operating-system specific code. The other ones all use generic code, and just a tiny bit of periphery which is necessary to communicate via native API calls at startup (one or two functions).

It's definitely doable. And if you use some kind of "virtual machine code" to execute your language's "instructions" or "functions," it almost becomes trivial. Of course, that is once you get it all setup to operate that way. :-)