Spring is a lightweight container, It allows Java developers who are building J2EE apps to get to the heart of their real domain problems and stop spending so much time on the minutiae of providing services to their domain. Spring is yet another tool in the open source family that helps developers build enhanced applications faster.
My experience with Spring is, that it is a big tool-box that offers a lot of features that you can use if you like or ignore if you don’t need or like it. Thats the positive thing about it, that (most) features are clearly separated from each other.
We, for example, do use Spring in our projects to benefit from it’s Hibernate support, component container and some others, but do the frontend with jWic instead of the spring MVC.