The Apache Tomcat project implemented the ajp* protocol with an NSAPI plugin for Netscape Enterprise Server. This NSAPI should also work with iPlanet Web Server, Sun ONE Web Server, Sun Java System Web Server, and the newly open sourced Open Web Server. The Tomcat ajp* NSAPI allows (Sun|Open) Web Server to act as the HTTP front-end and load balancer for Tomcat (similar to mod_jk).
