It was recently (2011) rewritten on top of Symfony2 -- http://symfony.com http://symfony.com -- and more importantly a modern, documented, and stable framework.

It was recently (2011) rewritten on top of Symfony2 -- http://symfony.com http://symfony.com -- and more importantly a modern, documented, and stable framework. It was likely done because finding quality PHP programmers is easier than finding quality Perl programmers.