Rather than coming up with a programming solution to protecting your work by making it a little harder to read, is it possible to achieve one of the following?

• Copyright your work.
• License your work to your userbase.
• Work out a contract with your users that protects your interests.
• Give away your work but sell support, maintenance, etc.
• Think of some other means of protecting your interests that doesn't involve obscuring your work by enveloping it into an executable.

My point is that creating an executable with the intent of simply making it more difficult to read what you've written (first) won't guarantee that you'll accomplish the goal, and (second) may not be the most effective approach. There may be better ways to protect your interests. Think a little outside the technical box and you may come up with a real-world solution that is more appropriate.