Chapter 1. Red Hat JBoss Fuse Overview

An OSGi bundle is a JAR file augmented with metadata in the JAR's META-INF/MANIFEST.MF file. Because the Red Hat JBoss Fuse container is fundamentally an OSGi container, the OSGi bundle is also the native format for the container. Ultimately, after deployment, all of the other deployment unit types are converted into OSGi bundles.

A Fuse Application Bundle (FAB) is a Fuse-specific deployment unit optimised for the JBoss Fuse container. FABs are a plain JAR built using the Apache Maven. FABs address some of the issues when using OSGi such as dependency resolution and class-loader conflicts. The FAB deployer in JBoss Fuse scans the metadata in the POM and automatically downloads any dependencies needed by the bundle.

A Web application ARchive (WAR) is the standard archive format for applications that run inside a Web server. As originally conceived by the Java servlet specification, a WAR packages Web pages, JSP pages, Java classes, servlet code, and so on, as required for a typical Web application. More generally, however, a WAR can be any deployment unit that obeys the basic WAR packaging rules (which, in particular, require the presence of a Web application deployment descriptor, web.xml).

A Java Business Integration (JBI) service assembly is the basic unit of deployment for JBI applications. A discussion of the JBI container lies outside the scope of this document. For details, see "JBI Development Guide".