Spring is a work in progress. It is a demo application intended to exercise the Essex libraries and help me learn a bit more about AJAX programming and what can be done with OpenSearch.
Spring is a part of of "a new project" to transparently design and build a better way of... ...well, a better way of doing any number of things.
Learn more about Spring in part 17 and part 18 of the ongoing series of articles about the new project.
Or if you prefer, jump right in a look at the Spring API.