We will manage your licenses for your software for free, our script connects to our webserver via PHP and validates the license. You can use API to build a Validator Script, so that you can enter a website and check it's license. You can add a specific domain to the site, or you can just offer a license key. It's automated, and is very difficult, or impossible to keygen. It doesn't just check a formula, it checks against a specific key in a license database in MySQL. Again, this is 100% free, just contact me an I will get your product and your account setup!