[zamalek]

"to my formers competitors you see?"

Basically you are pissed at them because they won in the market space. That's a perfectly normal and acceptable perspective to take. The only problem here is that you have only seen the one set of users that would get your code: your competitors. If you GPL'd your code they wouldn't be able to legally use it any way; in most cases.

The other set of users would be the [potential] contributors. They would take your code, improve it and bring it back into the repository. Eventually that open source repository would be worth more than anything your competitors would be able to put together.

Basically, from where I am sitting, open sourcing your code is the best path to getting revenge (face it, that's what you are after).

http://en.wikipedia.org/wiki/Scorched_earth