Tomcat 5 is a Servlet/JSP container that implements the Servlet 2.4
and JavaServer Pages 2.0 specifications from the Java Community 
Process. Tomcat includes many additional features that make it a 
useful platform for developing and deploying web applications and
web services.  Tomcat can be run as a standalone web server with 
Servlet and JSP support, or using Apache HTTP Server as its web 
server via the mod_jk Apache module (the www/mod_jk package).

See ${PREFIX}/tomcat/README.OpenBSD for
information on running Tomcat on OpenBSD.