| | A servlet is a generic server extension - a Java class that can be loaded dynamically to expand the functionality of a server. Servlets are commonly used with web servers, where they can take the place of CGI scripts. | |
| --Java Servlet Programming 2nd Edition - O'Reilly | |
Servlets are executed inside a Java Virtual Machine. To be able to run servlets, you will need the servlet classes (available from Sun Web site and a servlet container (also called servlet engine or servlet runner). The official reference implementation and most commonly used servlet container is Apache's Tomcat Server freely available from Apache web site (see also the section called JSP/Servlet server in the chapter called Getting and installing the software).