I've tried Thinstall and works with VFP EXE's. They say that is uncrackable. I don't know if it's true (I don't believe it, but I didn't find a decompressor/decrypter for it either, so maybe IS true). Compress and protect .NET executables too.
http://thinstall.com/
And about security
http://thinstall.com/help/programsecurity.htm

Dorin

>>Anyone found a protection against ReFox?
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>There is none.
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>>Should servicepacks protect our code?
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>They don't.
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>
>>Ionut,
>>There is no protection against ReFox, except ReFox.
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>Also known as 'extortion'. Even a VFP application branded with refox can still be decompiled though.
>
>
>>Decompilers work on VFP compiled code. If you purchase ReFox and use its "branding" option, ReFox will not decompile your code because it will respect the bytes inserted into your code base. However, this does not stop another decompiler from working on your code.
>>
>>In addition, Victor Anderson (sp?) has posted that he knows where the "branding" bytes are inserted and removing them with a simple hex editor defeats the branding altogether.
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>>Bottom line is that there is no sure fire way to protect your VFP code from people that really want it.
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>This is correct. About the only thing you can really do is to find some way to compress your .exe, so that it doesnt decompress until you run it (thus decompressing it in memory). Only thing is that even this won't completely protect you either. The makers of Refox have some other little gizmo called KONxiSE that does this. Problem is that once the .exe is decompressed in memory, you can do a memory dump and end up with the uncompressed .exe - then run refox or unfoxall or whatever on it.