The JBoss application server is not just popular because it's free...
What is JBoss?
JBoss is a popular open source application server that supports Enterprise JavaBeans (EJBs) and is compatible with with Java 2 Enterprise Edition (J2EE). In August, Novell announced it was bundling JBoss with SuSE Linux Enterprise Server 9.
The five-year-old JBoss application server is challenging the likes of IBM and BEA on their strongest ground and is attracting support from industry heavyweights.
One reason for the fast take-up of JBoss among developers and smaller software houses is that it is free - you pay for services, not software. But JBoss is beginning to compete on its own strengths, not just because it is doesn't cost anything.
Where did it originate?
JBoss was founded in 1999 by a team of Americans and Europeans with backgrounds in companies such as Sun, i2 and BEA. JBoss is also behind other open source projects such as Tomcat and Nukes.
What is it for?
The Eclipse-based JBoss Aspect Oriented Framework gives "plain old Java objects" (Pojos) access to the transactional and clustering support previously reserved for EJBs.
Analyst firm DH Brown said, "This is an interesting differentiator because Pojos are easier to programÉ most Java applications do not utilise EJBs, and hence do not get the benefit of some of the higher-end scalability features of some J2EE application servers."
What makes it special?
Sun's certification of JBoss as J2EE-compatible is a guarantee of compliance, but not of fitness for critical production use. As one analyst said, "J2EE certification reveals nothing about the suitability and quality of important elements of technical support, documentation, training and even to some extent, code quality."
However, Linux and the Apache web server have proved that open source software can enter the mainstream, provided it is backed by organisations offering commercial-strength services such as 24x7 support, training and consulting. Those backing JBoss include Hewlett-Packard, Computer Associates, Unisys and, after a history of rocky relations, Sun.
Other open source "middleware" initiatives include the Eclipse development environment and MySQL database - both have close links with JBoss.
How difficult is it to master?
The "Introduction to JBoss" course requires no prior knowledge of J2EE, and covers basic concepts such as EJB, JMX and Java Server Pages, as well as design patterns and best practices in application development. The Aspect Oriented Programming model is a painless route from Java development to the complexities of EJBs.
Where is it used?
JBoss says the software has been downloaded more than five million times in the past two years, and claims it is the most widely used Java application server among developers, and the most widely embedded Java application server among independent software suppliers.
What systems does it run on?
Partners that embed, bundle or resell JBoss products and services include Apple, Computer Associates, HP, Novell and Unisys.
Not many people know that...
Research group DH Brown thinks there is a "good possibility" the JBoss community may replace the Java Community Process driving J2EE.
What's coming up?
Continuous development of all aspects of JBoss through the worldwide open source community. The roadmap is updated monthly.
Rates of pay
Java developers with JBoss skills can look for £23,000-£45,000 depending on seniority, and more in the banking sector.
Classroom training is on offer from JBoss partners. See www.jboss.org for a schedule; you can also download the software.