That's right, thanks to Caucho, you can run PHP scripts on the Java platform! It uses the Resin application server to compile PHP scripts down into Java bytecode.

Read all about it here. Some of the highlights are:

- Applications can take advantage of features like connection pooling, distributed sessions, load balancing, and proxy caching

- PHP applications can choose to use Java libraries and technologies like JMS, EJB, SOA frameworks, Hibernate, and Spring

- Quercus claims to outperform mod_php by about 4x some applications

- Make use of Java profilers to get in-depth information about the PHP application performance

- Write PHP extensions in Java

It works very nicely indeed. I had Drupal 4.7 up and running with almost zero fuss. I had to remove a particular PEAR library dependency for a module that I wrote. I'm pretty sure I could replace this with a custom Java PHP extension though.

As Resin is a Java application server, you can also run ColdFusion! I deployed CF in WAR form and so far, it all seems to be 100% working. I've got blogcfc and a couple of other applications working.

Hopefully I'll post some more after I've had a chance to experiment further.