What is tomcat?

To get a servlet executed, you need a webserver program capable of executing Java bytecodes.
One possibility is to use tomcat, a webserver program provided by the Apache Software Foundation.
In a recent survey by Netcraft of IP addresses running servlet engines [33],
tomcat, Resin and IBM are equally popular and together have 75% of the market .
Although tomcat is great for running servlets, it is not a very efficient webserver.
So another possibility is to use Apache's HTTP Server program (httpd) as a webserver program ...
... with it configured to run tomcat to execute servlets.
However, here we will keep things simple: ...
... we will just use tomcat on its own.