A J2EE application server born open
JBoss Application Server 4.0 was released in late 2004 (version 4.0.0 in September, 4.0.1 in December 2004) as the first Open Source application server certified J2EE 1.4 by Sun Microsystems. Developed by JBoss Inc. — founded by Marc Fleury — under LGPL, it represents at that moment the most mature alternative to the dominant commercial products (BEA WebLogic, IBM WebSphere, Oracle AS) for deploying J2EE applications.
What 4.0 includes
- Full J2EE 1.4: EJB 2.1, Servlet 2.4, JSP 2.0, JMS 1.1, JNDI 1.2, JTA 1.0.1B, JCA 1.5, JAAS, Web Services (JAX-RPC 1.1, SAAJ 1.2)
- Apache Tomcat 5.x as embedded web container — replacing Jetty as default
- Hibernate 3 as JPA-predecessor for persistence
- JBoss Messaging (JBossMQ evolution) for JMS
- JGroups for multicast clustering
- EJB 3 preview (available in beta; full support in AS 5)
- JMX Console and Twiddle for runtime management
The microkernel architecture
JBoss AS’s distinctive architectural trait is the JMX microkernel: the core is a JBossMX implementation of JMX 1.2, and all services (datasource, deployer, transaction manager, messaging, security) are MBeans dynamically loaded. Configuration is declarative via XML files in deploy/:
- Dropping a
.war,.ear,.sar,.rar,.jarin the active deploy directory activates the component - Hot deployment without restart
- MBean dependencies handled automatically
The model is flexible and modular: unnecessary MBeans can be removed for embedded scenarios or added for specific needs.
Typical deployment stack
An enterprise application on JBoss AS 4 typically follows this stack:
- Struts 1.x or Tapestry or Spring MVC for the web layer
- EJB 2.1 Session/Entity Beans (or Hibernate 3 directly) for business/persistence
- MySQL, PostgreSQL or Oracle as database
- JBoss Cache (TreeCache) for distributed caching
- JGroups for cluster communication
- Apache HTTP Server + mod_jk as front-end with load balancing
The JBoss + PostgreSQL + Apache combination on Linux becomes a standard stack for Java applications in Italian public administration and companies in the mid-2000s.
Licence and business model
JBoss Inc. adopts an open core model avant la lettre: LGPL code freely accessible, with commercial subscriptions (JBoss Enterprise Application Platform, later JBoss EAP) offering extended QA, 24x7 support, legal indemnification, certified patches. LGPL allows use in proprietary commercial products without extended copyleft obligations.
Open Source competitors
The scenario in December 2004 for Open Source Java application servers:
- Apache Geronimo — in preparation as J2EE 1.4, ASF backing
- Apache Tomcat — servlet container, not a complete J2EE application server
- JOnAS — ObjectWeb, EJB 2.x, used in French context
- JFox — less widespread
Among these, JBoss AS is the most mature and widely adopted, with a community dimensionally comparable to commercial vendors.
Italian adoption
In the Italian IT ecosystem 2004-2005, JBoss AS is the natural choice for:
- Public administration — front-desk platforms, regional portals, back-office systems
- Medium-sized banks and insurance — alternatives to expensive commercial products for internal projects
- Telco — OSS/BSS, self-care portals
- Italian software houses distributing multi-client Java applications — LGPL facilitates bundling the server with the product
JBoss training and certifications spread through JBoss Authorized Training; several Italian universities integrate JBoss into Software Engineering courses.
Ecosystem tooling
Around JBoss AS an ecosystem grows:
- JBoss IDE — Eclipse plugin
- Hibernate Tools for reverse/forward engineering generation
- Seam (after 2005) — integration framework JSF + EJB3
- JBoss Portal for JSR-168-based portals
- Drools (discussed elsewhere) — enters JBoss orbit and later Red Hat
Historical role
JBoss AS 4 consolidates the idea that quality Java enterprise middleware can be Open Source. Before its arrival, the typical choice for production J2EE applications was a proprietary product with substantial licence costs. JBoss proves that LGPL + commercial subscriptions is an economically sustainable and competitive model, paving the way for a whole generation of Open Source middleware dominating the second half of the 2000s.
The impact on the Italian market is bound to be lasting: many Java enterprise applications started on JBoss in these months can stay in production for years, following the server’s evolution.
References: JBoss Application Server 4.0 (September-December 2004). JBoss Inc., Marc Fleury. LGPL licence. J2EE 1.4 Sun Microsystems certification. Embedded Apache Tomcat. Hibernate 3. JMX/JBossMX microkernel.