Java Servlet technology provides Web developers with a simple, consistent mechanism for extending the functionality of a Web server and for accessing existing business systems. A servlet can almost be thought of as an applet that runs on the server side--without a face. Java servlets make many Web applications possible. »Read More
The reference implementation is included in the Java EE 5 SDK and also in the open-source Java Platform, Enterprise Edition (Java EE) application server, available through the GlassFish project, on java.net. The reference implementation source code for Servlet technology is available from the svn repository on java.net. Additional information on all webtier technologies in GlassFish can be found at the GlassFish Webtier page.
Learning GlassFish for Tomcat Users This paper demonstrates that the Web container capabilities provided by GlassFish offer superior extensibility, scalablity, and usability compared to those of Tomcat—without sacrificing performance.