JBoss Inc. on Monday is shipping JBoss Application Server 4.0, which the company is billing as the first open source application server certified as compatible with the J2EE 1.4 platform.

Formerly, JBoss had been in a dispute with Java founder Sun Microsystems Inc. over whether to certify the application server and pay the costs involved. But the advent of Version 4.0 means the product has passed the 23,000 tests in the J2EE 1.4 Test Compatability Kit, according to JBoss.

“Other products have achieved J2EE 1.4 certification, but this is the first open source application server that has been certified,” said Marc Fleury, chairman and CEO of JBoss.

The application server is downloadable for free at http://www.jboss.com/downloads/index under the Lesser General Public License, which the company says offers the least-restrictive uses for business of all the open source license formats. JBoss sells support services and training for the product, with prices starting at US$10,000 and scaling into the millions of dollars.

JBoss is touting the Aspect Orientation (AO) functioning in the application server. AO presents a modular way of designing application servers so users can remove and add different parts. “With AO, we achieve more (modularity), more performance in middleware, and more flexible middleware,” Fleury said.

JBoss offers clustering of Java objects, including EJB, JMS, HTTP, and “Plain Old Java Objects,” the company said. Also featured is a customizable footprint, in which the architecture leverages JMX extensions to enable users to tailor the footprint. Additionally, services can be added based on user needs.

The product is integrated with JBossCache, providing transactional distributed cache, as well as the Tomcat 5 open source Web container. Also featured in JBoss is Hibernate 2.1, which is an object-relational engine providing Plain Old Java Object persistence and a smooth transition to EJB 3, said JBoss.

The JBossIDE portion of the product provides developers with functions such as server life cycle control, debugging, EJB packaging, and deployment.