Tomcat is a relatively new platform for Web development created by the Apache Group and Sun Microsystems. It’s a combination of the Apache Web server and Sun’s server-side Java technologies, including JSP (Java Server Pages) and Java Servlets. Tomcat is the reference implementation for these technologies, so all other implementations will look to Tomcat for standardization.

Javabeans and a nice Chianti
The Tomcat product allows you to use your existing Java classes and beans in an Internet environment. By creating your own Java Server Pages, you can embed Java and HTML into a single page, much the way Active Server Page developers can embed ActiveX controls and HTML into their documents. But unlike ActiveX components, Javabeans can easily move between platforms.

Tomcat compiles your Java Server Pages just before running them. Because Tomcat is built on Java technology, it gives you a fair amount of scalability. You can start developing on a small server today and move to an RS/6000 S70 (or a cluster of them) when you need to—without rewriting your Web application. This, combined with the distributed nature of Java, allows you to build much more complex applications and integrate with other systems using Java technology.

But we’re already using servlets!
It’s all right if you are already using servlets, because Tomcat supports both JSP and Java Servlets. While JSP documents contain both HTML and Java, Java Servlets contain only Java code. These are not necessarily competing technologies, just different ways of implementing the Java language for Web applications. Java Servlets are Java classes that have special interfaces for handling calls from the Web server.

When Tomcat sees that you are using a servlet and not a JSP document, it simply runs the compiled Java class. The Java class in turn handles the request and generates the output. If you’re using servlets today, you should have little difficulty implementing them on Tomcat.

Is Tomcat open-source?
The Tomcat is an open-source product. It’s developed under the Apache license. So, if you’re using Apache today, you can use Tomcat today. While Sun maintains control and responsibility for the Java technologies used by Tomcat, the Tomcat product is still an open-source development project and is looking for other developers to get involved and help further it.

Currently, you can download both binary and source versions of Tomcat. There are three binary builds that you can get—but the Release Builds are the recommended versions. The Milestone and Nightly builds are mainly for developers. As of this writing, 3.0 is the latest release version. You can also get the three versions of the Tomcat source, including Release drops, milestone stops, and snapshots. Again, unless you are a developer and willing to work with the source to make it work, you should probably stick to the release versions.

Are JSP and Java Servlets legit?
JSP and Java Servlets are legit! Many companies, including BEA, IBM, and Netscape, have products that implement these technologies in commercial products. BEA’s WebLogic is a leading application server product. ATG’s Dynamo Application server runs the TechRepublic site. Bluestone’s SapphireWeb and IBM’s WebSphere are other popular application servers. NetObjects fusion, Oracle Application server, and Allaire’s JRun also support these technologies.

While these companies are providing the tools to create Java-enabled Web applications, other companies are implementing this technology. Sites such as ColumbiaHouse, the popular music retailer, provide rich applications and functionality to their users through Java-enabled Web servers.

Let me at it
Tomcat is a joint effort between Sun and the Apache Group. You can get more information and download the latest Tomcat version from the Apache Group. Sun also maintains separate pages for Sun JSP and Java Servlet technologies. To become an active part of the Tomcat project, visit the Apache Group’s Get Involved page.