Getting Spring framework

I am using MVC in my Tomcat 4.1.27 but never used Spring. I have done very little work with Struts.
If I want to start using Spring do I need to download any Jar files from a Spring site? What is the difference between Spring and Struts.

I am using MVC in my Tomcat 4.1.27 but never used Spring.

What motivates you to use Spring then ?

A simple working MVC would not justify using Spring, wouldn't it ?

If I want to start using Spring do I need to download any Jar files from a Spring site?

You'll find the latest 2.0.x and 1.2.x here. You can download zip files with or without dependencies.

What is the difference between Spring and Struts.

From my point of view, Spring is much more. Struts was made to be used with a web application. Spring offers you much more services. They have different purposes. There's a part of Spring called Spring MVC, which could be compared to what Struts does, in a different way. If you plan to start with Spring, I'd recommend you to get a book.