Looks like JBuilder thinks you are working with JBossAS 4.0.x - that is where the server jar is located in those versions (such as 4.0.5). For JBossAS 4.2.2, the servlet JAR is located at server/default/lib/servlet-api.jar. I do not know how to change this in JBuilder. Also, after you fix this one, you will probably run into several more missing JARs that have moved. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4164287#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...