I am looking for a good JSP/Servlet engin to install it on a server that will run few 100's of sites (vertual hosting). I know that there are many implementions out there, but I am looking for one that is :

- Easy to configure for shared envirnoment.
- Suitable for commercial use (I am not using it for production on my personal machine )
- Not a system resources HOG!
- Capability to provide private JVM for eache vertual host.

Thanks in advace