[orib]

One interesting point to note it is certainly not an issue to sell the source to your program in a bundle with the binaries, allowing enterprising hackers to modify and update the software. You could even allow distribution of these changes.

Allowing this doesn't mean that you are forced to give up copyright on the source, or release it under an open source license. A license that says "You may have, modify, and distribute modifications to the source, but not duplicate or redistribute it" is certainly something that I would find interesting, and would love to see more software released under.

[cschwarm]

You may like to look at the license used by TheKompany [1].

[1] http://www.thekompany.com/products/licensing.php3