I guess PHP programmers should never expect anything more than a backhanded compliment. I just love how any topic that just contains the word PHP immediately gets a comment on how awful it is - even if PHP isn't really involved in it.
It doesn't run in PHP, but it borrows function signatures from PHP's core library. One of the most common complaints about PHP is that the core library is messy and inconsistent.
edit: I didn't mean to sound so negative. I think this is pretty cool if taken for what it is. Despite the messiness of PHP's libraries, they are well documented and cover a lot. The string, date, and array libraries in particular are quite useful.