We at Zend have open source PHP in our blood (see Zend Framework, Zend Opcache, etc). If you contribute to PHP open source projects, you are making the world a better place to develop in. And we want to thank you for your contributions!
If you are a top-50 contributor to a PHP GitHub project with over 2,500 stars, we want to give you a free copy of our professional software — Zend Server Enterprise Edition and Zend Studio, together worth over $10,000. They are fully supported and can be used for production on a single server.
All we ask is that you keep contributing to the open source community, with our thanks.
(Oh yeah, and product feedback would be nice!)