What are servlets? "Servlets are modules that extend request/response-oriented servers, such as Java-enabled web servers.
For example, a servlet might be responsible for taking data in an HTML order-entry form and applying the business logic
used to update a company's order database.
Servlets are to servers what applets are to browsers.
Unlike applets, however, servlets have no graphical user interface.
Servlets can be embedded in many different servers because the servlet API,
which you use to write servlets, assumes nothing about the server's environment or protocol.
Servlets have become most widely used within HTTP servers; many web servers support the Servlet API.
Servlets are an effective replacement for CGI scripts.
They provide a way to generate dynamic documents that is both easier to write and faster to run.
Servlets also address the problem of doing server-side programming with platform-specific APIs:
they are developed with the Java Servlet API, a standard Java extension." (The Java Tutorial/Sun Microsystems)
What is the Jakarta Project?
"The goal of the Jakarta Project is to provide commercial-quality server solutions
based on the Java Platform that are developed in an open and cooperative fashion.
The flagship product, Tomcat, is a world-class implementation of the Java Servlet 2.2 and JavaServer Pages 1.1 Specifications.
This implementation will be used in the Apache Web Server as well as in other web servers and development tools." (The Apache Software Foundation)