You have lots of choices. You can run Tomcat on its own, you can run Apache httpd together with Tomcat. You can run one of the many other servlet servers (Resin, JWS etc.) on its own. You can run one of the many plug-in servlet containers with a web server such as Apache httpd, IIS, iPlanet etc.
If you want to get started as simply as possible, I recommend using one of the pure Java servlet servers on its own. Tomcat is the reference standard, and is available for download from
http://jakarta.apache.com/ , but Resin is my personal favourite, and seems to be easier to install and get running that Tomcat. Resin is available for download from
http://www.caucho.com/ .
[This message has been edited by Frank Carver (edited November 27, 2000).]