I've just recently discovered
Zephir. I must say, these are awesome projects! I've always postponed contributing to open source projects for lack of time but these ones have to be an exception. For me Zephir is a dream come true.
The compiler watches your Zephir directory and automatically compiles your extension whenever you make some changes. It will also restart
php-fpm. So you will be able to have realtime feedback from your compiler whenever you save your changes. If you want to test in a web browser just save your work and go to your browser. No need to compile manually.
You will find both projects on Github: