I first started looking at Object Persistence technologies because I wanted to write a
JarSearcher application. I could search the store for any class. Frequently when I'm compiling someone else's code, I find class references that I'm unfamilar with and don't know which Jar file the class is in. My
JarSearcher would pre-search Jar files so that I could quickly find the class that I need.
http://www.codebits.com/prevayler/