The JBoss server application (also known simply as JBoss AS) is an application server based on Java. It is a free software (or open source) server and is usable in any operating system supported by Java (because the server is Java based).
Apache Tomcat (also know as Jakarta Tomcat, or its more widely known name, Tomcat) is a servlet container (meaning it is a Java class that operates under the strictures of the Java Servlet API – a protocol by which a Java class responds to an http request). This is an open source server, providing a ‘pure Java’ HTTP web server environment in which code written in Java is capable of running.
There are many permutations of the JBoss AS server application. The JBOSS AS 4.0 version features a Tomcat 5.5 servlet container that is embedded in the application. Because it is compatible with any Java Virtual Machine between versions 1.4 and 1.6, JBoss AS is capable of running on a variety of operating systems -which includes any of the POSX platforms, such as Linux, FreeBSD and Mac OS X. JBoss AS 4.0 is also capable of being run on Microsoft Windows, and an assortment of other platforms – that is, of course, if a JVM that is suitable for the platform is readily available. Though the JBoss AS 4.2 version also operates with a Java EE 1.4 application server like the 4.0 version, it only functions with the aid of version 5 of the Java Development Kit. It deploys Enterprise JavaBeans 3.0 by default, and is also bundled with a version of Tomcat (version 5.5). The most current permutation of the JBoss (version 5.1) operates the same as its predecessors, but it also contains a preview of the impending Java EE 6 specification.
There are several components in the Tomcat servlet: Catalina, Coyote, Jasper and Jasper 2. Catalina makes use of the Sun Microsystems specifications specific to servlets and JavaServer Pages (or JSP). Coyote is the HTTP connector associated with Tomcat. As such, it watches for incoming connections on a specific TCP port on the server, forwarding the request to the Tomcat Engine for processing. Jasper and Jasper 2 function as Tomcat’s JSP Engine. Jasper 2, however, includes a JSP tag library pooling, background JSP compilation, and is capable of recompiling JSP when included pages change, and a JDT Java compiler. JBoss has the ability to do all of these actions as well as a variety of different functions, including, but not limited to, clustering, distributed deployment (farming), and using Java Management Extensions.
1. JBoss is a server application based on Java; Tomcat is a servlet container.
2. JBoss makes use of the Java EE specification; Tomcat makes use of Sun Microsystems specific specifications