This project is just a collection of katas for php programmers. To play with it, just clone the repository and start implementing the missing things, so that all tests succeed.
The katas don't solve complex problems, but can be seen as simple riddles. If you solved one, you always should have a second or third look to it and try to refactor it.
$ git clone https://github.com/nicolask/kata-collection
$ cd kata-collection
$ composer install
run tests
$ ./vendor/bin/phpunit tests