First of all, why not? Everything else can run on the jvm (yes… even c#), so why not php? Well… I certainly don’t see why not… Java is a fairly robust language with a pile of different libraries and (as you saw if you clicked on any of those links) languages that can run on it. It is ideal!
Don’t like php’s random function? Why not use Java’s? Not your cup of tea? Use ruby’s instead, or python’s, or write one in COBOL if you are really brave.
It also means that you can implement the functionality in Java, the database transactions in Ruby, then write all of the presentation in PHP, no clearer MVC separation than that eh? Admitedly it might get a bit confusing and I may be over exaggerating about the possibility of these implementation’s cross communication abilities… but it would be great if you could (I might test it later…).
Go check it out!