The php/Java bridge is an optimized, XML-based network protocol, which can
be used to connect a native script engine, PHP, with a Java or ECMA 335
virtual machine. It is more than 50 times faster than local RPC via SOAP,
requires less resources on the web-server side, and it is faster and more
reliable than direct communication via the Java Native Interface.

J2EE back end clustering and Apache load balancing are supported as well as
running PHP scripts within JSP, JSF or other frameworks.

The php/Java bridge allows you to quickly access java classes from within
your PHP scripts without having to know Java. It also allows you to access
PHP scripts from within your Java classes without having to know PHP.

WWW: http://php-java-bridge.sourceforge.net/