I'd like to ask the Java pros here a question about my current study that I am about to do - what are the key contributors to the differences in efficiency of various servlet containers? I need to compare Tomcat/JBoss/Glassfish/Jetty etc. and I need to know what "factors" may affect the results in the most significant way? I am going to write mock applications for that purpose, so any recommendation for a Java feature/framework/library etc. that I might implement there so that I can greatly increase the load of the containers (actually the containers, I do not care about the load of the machine since I am going to run all the tests on the same machine of course), would be appreciated! I need the study to be as objective as possible. Thanks for any help guys!