Benchmark tests show that Caucho's Java implementation of PHP, Quercus, performs faster than PHP on Apache. Quercus, a Java servlet that runs in Resin or in any other Java app server, uses just-in-time compilation to convert PHP code into optimized Java code, which is then compiled into bytecodes.

Read all the details: http://www.developer.com/white_papers/article.php/399374/Faster-PHP-Through-Java.htm