Php fun sites

Question

Are there any sites where we need to solve puzzles using php scripts? Like a PythonChallenge ?

I know most programming sites, the idea is to find a site that can help you discover the power and specialty of PHP. A script how PythonChallenge does this using a wiki for each level.

Answer 1

http://projecteuler.net/ has programming and math problems that can be undertaken in any language.

Answer 2

http://projecteuler.net/

mostly mathematical problems, most of them can be done using php.

Answer 3

code golf. .