>>>Certainly yes
>>>
>>>>Are there tools to decompile VFP .EXE file to get source code?
>>
>>Yes. Two of the popular ones are ReFox and UnFoxAll, but are others.
>>
>>>>
>>>>Are there ways to make your .EXE such that those tools would be unable to decompile the .EXE?
>>
>>There are tools that will make it more complicated, but not impossible.
>
>Refox had a 'Branding' options which made it impossible to decompile if you don't have the branding password... but as any other password, a patient person with processing power available could break it. I don't have the latest Refox version so I'm not sure if that option's still in there.

Nope... even without the password you can get the source in like 2 seconds. This is done by editing the refox.exe itself with a hexeditor. Once you done this you can decompile any 'branded' app without the need for the password. I've TRIED talk to the makers of refox about this flaw, but I'll spare you my rant about it.