I can't share in Marilyn deQueiroz's sweeping generalization about JRun. JRun has it's weak points and limitations, but I would not call it "horrible".
When cost is a serious factor, and you don't need limitless scalability, JRun is a very good choice. JRun 3.1 is J2EE Certified, and we have a couple medium traffic sites running JSPs and EJBs on JRun.
One of JRun's serious weak points is how it handles it JNDI (which greatly limits it's scalability).
BTW aanchal mathur --
You shouldn't be using JRun's internal web server in a production environment,
you should connect to a web server like Apache, iPlanet or IIS. The webserver that comes with JRun is for development purposes only.
------------------
Sun Certified Programmer for the Java� 2 Platform
[This message has been edited by D Broadway (edited September 21, 2001).]