I was doing a small list of PHP MVC framework (like Zend, CakePHP, Yii etc...) and I noticed that all of them are open source.Then I tried to find some proprietary framework, but my research was unsuccessful.Is there any  proprietary PHP MVC framework? Why they are so few(if there is any)?
Is there any proprietary PHP MVC framework?
php;frameworks;mvc
The reason you're not finding anything is probably quite simply a matter of economics - existing open source frameworks are pretty decent these days, and they can be used (and extended) free of charge by the very nature of open source software. Any proprietary competition would have to offer significant extra value to make up for the cost and added inconvenience (no access to the source code, possibly license enforcement, legalities, etc.).That's not to say no such frameworks exist, but they probably cater to quite specific niches.