I might not be able to answer your main question  but I should say Tomcat has earned some credit in the production world too. I have personally used it in a high transactional system  and it did held water. I admit there was some secret sauce involved in the mix but it was not anything that would raise any eyebrows.

I think you are asking a strange question. tomcat  is a web server  engine, but Weblogic and Websphere are both enterprise server.

It is comparing apples vs oranges in this case.

The enterprise server is much more than a simple web server.

Let’s go back to the question  you asked. I think you will find out you are perfectly safe within tomcat. Because Spring framework  is good without EJB. In other word, Spring takes care of all the EJB work for you so you don’t have to use the EJB container.

So if you simply want a server that will serve to the web. Tomcat is your right tool.

If you do want to go fancy, I will recommend you to start trying Glassfish server. Glassfish server is an enterprise server yet it is open source. Even though Oracle bought Sun, this project has not gone under yet. If you do not like the name of Oracle, you still have another open source enterprise server called JBoss.

We used tomcat  on a production system  with high load and traffic and it works fine.
First, try tomcat and if you had a problem then think of commercial software.

we were using Websphere with Spring in DPI
it needs some patches to fully integrate Spring in extra features provided by Java EE container like transaction management.

Here's all you have to know for integrating Spring/Hibernate/... with Websphere: www.ibm.com/.../0609_alcott.html

Btw websphere  is not worth trying. tomcat  is just great, and with MuleSource's TCat server  or SpringSource's server product it's got great management features too. But if you need some features that tomcat doesn't provide or you have to integrate third party libraries to add those missing features to tomcat and it's more headache then trying Weblogic makes sense. Websphere is only good if you are forced to use it because you're in an IBM shop.

I have used weblogic  10 and it is very good for EJB3 and seam but i don't know for spring.

Regarding the download you can easily download it from the Oracle website without any limitation.

you can download weblogic  from oracle site

i dont know about webspher

i work with glassfish . i think it is better than weblogic

advice you look at it

I found using websphere  hard to try (because of IBM company )
I downloaded  weblogic  , .... there is more document about it .

The main reason I thought using another server  , instead of tomcat  , is my application  is high transactional (about 100 per second)... I tested with Jmeter and it could handle about 60 processes per second . (more than that it crashed) ... so if you can guide me to tune tomcat in a way that
work with these number of transactions , I really prefer to use it , ( so better than trying a new one).

Maybe it is not only the server  to be reconsidered. if you don't use any grid technology, clustering and stuff like that, using a more complicated server may worsen the situation. I believe you need to restructure the application  and cluster it.

I didn't try Weblogic. But I had to work with Websphere on Z/OS and Windows for one past year. It is just like a nightmare. Incompatibilities, many parameters you have to know and set correctly and lack of documentations and lack of resources will make troubles.
Development using Tomcat is more easy. If you are not going to server  huge amount of process, use the simplest one.