Kohana is a very nice project when you are forced to use PHP to develop a webapp, it's quite simple to use and fast.

The community forums are active and friendly, the only lack I saw (some time ago) was the documentation, but the code is very clean and well documented with concise and clean comments.

I used it right before my complete switch to RoR, I was happy with it, but php is still the big poorly designed language-mess which has always been.