I'm an OJB user, I've been using OJB since 0.8.375.  I had thought I had picked a winner when it was announced to be a Jakarta project.  However, there's another OR-mapping framework that's been gaining traction lately,  Hibernate.  I was intrigued that it has moved so quickly to version 1.2, while OJB had inched along to version 0.9.7.  Could they be a little too liberal with their version numbering?  I decided to investigate it a bit deeper.

I read the reference documentation, and I must say I am impressed!  I've worked with TopLink, arguable the best OR-mapping tool in the planet, so I think I know what to look for.  Hibernate has features that I've never seen before, such as Collection Instance Management, Component Types, Many-To-Many Polymorphic Associations and Outer Join Fetching.  OJB has many restrictions on what you can map. Based on the document alone, Hibernate is definitely without a doubt better than OJB for OR-mapping.

How and why did this come about?  My guess is that Hibernate's goal is "Build the best OR-mapping tool in the planet".  OJB's goal however is more like "Build the best ODMG/JDO tool in the planet".  In my opinion, that's a big mistake,  JDO and best OR-mapping tool are in my opinion a contradiction. 

In order to compete, its time for OJB to rethink its priorities.