Quercus is a high performance implementation of PHP and meets or exceeds the performance of the C PHP implementation with common PHP applications. The Quercus compiled code provides significant performance increases over the traditional C based implementation of PHP. Benchmarking has shown that Quercus is 4 to 6x faster than mod_php, 10% faster than eaccelerator. When used in conjunction with Resin, static files are served faster than Apache.

Quercus alleviates many of the scalability issues faced by traditional deployments of PHP applications. The thread safe libraries provide for the possibility of servicing requests without the overhead of requiring many processes. The single process provides the ability for effective database connection pooling, even amongst separate requests, greatly reducing database load and the cost of connection establishment. With the ability to provide services directly with Java libraries, custom code and proprietary functionality developed in Java is available directly to the PHP application and does not require difficult to scale solutions such as web service client/server architecture.

Many of the security concerns of traditional PHP deployment are addressed by Quercus. As a Java application, Quercus is not vulnerable to many of the security dangers of the traditional C based PHP interpreter. As a clean room implementation of the PHP language and libraries, Quercus provides a comprehensive single code base and benefits from tighter quality assurance.

Quercus and Quercus' PHP libraries are written in Java, thereby taking the advantages of Java applications and infusing them into PHP. Quercus presents a new mixed Java/ PHP approach to web applications and services where Java and PHP are tightly integrated with each other. This architecture allows PHP applications and Java libraries to exist within the same process. To facilitate this new Java/PHP architecture, Quercus provides an API and interface to expose Java libraries to PHP. PHP applications can choose to use Java libraries and technologies like JMS, JPA, EJB, SOA frameworks, Hibernate, and Spring. PHP applications can also directly consume proprietary services and functionality developed in Java. Java applications can choose PHP as a view technology, exposing existing code including JavaEE and Spring based libraries to PHP developers and designers.

Quercus compiles PHP code to Java byte code. Compilation is performed in the background, allowing the rapid execution of code in interpreted mode during development and providing high performance of compiled code in production - automatically.

A common problem with traditional PHP is the inability for the servers to pool connections to the database. Without database connection pooling, sites reach a point where they are no longer able to increase capacity by adding more servers because the limit of establishing network connections has been reached.

Quercus automatically pools database connections, existing applications automatically gain the benefits of connection pooling, customization of pooling parameters is also available.

Quercus has no external dependencies and implements all of the extensive functionality available in the PHP library. Applications written for or tested with Quercus are developed in a homogeneous environment, deployment on other servers are guaranteed the same environment.

Quercus enables PHP based applications to take advantage of the many enterprise grade features of JavaEE and other third-party libraries. Quercus includes functions for retrieving beans in a Spring environment, a Resin environment, or through the use of JNDI.

Quercus has thread safety and executes each script in it's own dedicated thread. Because Quercus is threaded and not process based, it is now possible for PHP applications to take advantage of the benefits of shared resources, including caching and efficient storage of distributed sessions.

The interpreted mode of Quercus runs in any Java container. The open source GPL Quercus application brings the ability to use PHP in any web application, or via the standard mechanism provided by JSR 223.

See quercus.caucho.com for more information about Quercus.