Do you like profiling? Do you like tuning code? If you do, how about taking part in the db4o performance contest? We offer USD 6000 in prizes for the best contributions to make db4o faster.
We have made it very easy for you to get started by providing an Eclipse workspace set up with the db4o sources and the Poleposition benchmark.
Links to get you started:
Performance Contest page
"Getting Started" video
Performance Contest Forum
The contest has been running for a month already and we are seeing first contributions coming in.
Andrew has improved sorted queries and provides a UTF-8 string encoder.
Erik is working on a query cache to make queries reusable.
Can you beat their patches? I am sure you can.
The contest is still open for contributions for one more month until August 15.