There are three well known implementations of the PHP scripting language:
v The original implementation of PHP and the de facto standard is the open source PHP distribution.
v Project Zero has a PHP runtime written in Java. It also distributes extensions from the open source implementation of PHP.
v Quercus is an open-source pure Java implementation of the PHP scripting language.
To bridge between PHP scripts and Java libraries all three implementations provide a PHP/Java bridge.
The de facto implementation of PHP has a PHP/Java Bridge separately available from SourceForge. This uses a dual process model where the Java libraries are run in a separate process from the PHP runtime. Interactions with Java objects are marshalled across to the Java process using an XML protocol.
Quercus and Project Zero implement PHP on top of the Java Virtual Machine and so can run the Java libraries in the same process as the PHP runtime. This reduces the overhead of interacting with Java libraries when compared with the dual process model.
v Quercus (software)
v Open source PHP homepage
v SourceForge PHP/Java Bridge homepage
v Project Zero homepage
v Quercus homepage
1. http:/ / php-java-bridge. sourceforge. net/ pjb/ PROTOCOL. TXT
2. http:/ / www. php. net/
3. http:/ / php-java-bridge. sourceforge. net/
4. http:/ / www. projectzero. org/ documentation/
5. http:/ / quercus. caucho. com/