This is something I actually tried one time (at first by mistake).

I had a VFP6 EXE ... and inside that VFP6 EXE I had a RUN command that executed a VFP9 exe. Interesting thing was that it DID work, yet the machine I tried it on didn't have the VFP9 runtime files on it.

Rather interesting, eh? So anyone know what happened there? I assume that the VFP9 EXE, since it was called from a VFP6 EXE, ended up using the VFP6 runtimes. Does that mean my VFP9 EXE that was running ended up with all the features of VFP6 as a result? So like engine behavior was set to 70 on it's own?

It's been about a year since I stumbled across that - I don't even remember if I posted anything about it out here or not.