title: When to use JCR (content repository) over other options?
body: <p>I'm trying to evaluate content repositories (<a href="http://www.jcp.org/en/jsr/detail?id=283" rel="noreferrer">JSR283</a>) like <a href="http://jackrabbit.apache.org/" rel="noreferrer">Jackrabbit</a> and <a href="http://www.jboss.org/modeshape" rel="noreferrer">ModeShape</a> but I must confess that I don't understand what problem resolves in first place and even if it is a good choice for the project. Which cases do you think is the best solution to apply? Is not the same thing as relational databases, except for the size? Why? Extra points for pointing real world examples.</p>
  
  <p>Thanks in advance.</p>