Java servlets are server-side Java programs that application servers can run to generate content in response to a client request. Servlets can be thought of as applets that run on the server side without a user interface. Servlets are invoked through URL invocation or by other servlets.
Sun Java System Web Server 6.1 supports the Java Servlet 2.3 specification.
Java Servlet API version 2.3 is fully compatible with versions 2.1 and 2.2, so all existing servlets will continue to work without modification or recompilation.
To develop servlets, use Sun's Java Servlet API. For information about using the Java Servlet API, see the documentation provided by Sun at:
http://java.sun.com/products/servlet/index.jsp
For the Java Servlet 2.3 specification, please visit:
http://java.sun.com/products/servlet/download.html
For information about developing servlets in Sun Java System Web Server, see Chapter 3, Using Servlets.