Quercus is Caucho Technology's 100% Java implementation of PHP. This technology is taking off not only because of the trend toward scripting in the Java community, but also because of the performance and reliability that Java adds to PHP. In this talk, we will present the compelling reasons to use PHP on Java including availability of applications, ease of view development, and performance improvements of up to 89% over PHP with APC. We will show specific use cases of Quercus such as using popular PHP applications like MediaWiki, WordPress, and Drupal directly, bridging existing Java and PHP applications, and using PHP as a view technology for Java. We will also show the unique capabilities of the Quercus implementation such as transparent clustered sessions, the use of Java objects natively from PHP, and even interactive game development in PHP. Finally, we will look at case studies of real Quercus deployments such as LiveProcess, the leader in emergency preparedness' planning for the healthcare industry, and others to see how these applications take advantage of PHP on Java.