Perl will be out-ot-date since it has limited functions. Now, for big system, JSP(Java Server Page) and XML are the first choices and Tomcat and IPlanet will support Java servlet. And if you want to develop the Web Server with strong communication abilities, for example, using multiagent for searching, you'd better use JSP on Tomcat, .NET Frame, ect. I recommend you use JBuilder Enterprise which support XML and has the Tomcat installed to develop and debug the web server.