Looking to contribute to a high peformance Open Source library in Java. This may be a good place to start.
There is a number of ways to contribute to OpenHFT/Chronicle Software. You need to;
fork one of the projects,
try an improvement such as adding documentation, a unit test, or a fix.
issue a Pull Request.
I am not familiar with these projects
A good way to get a feel of these projects is to look at our projects web site
I also suggest you read this blog as it contains more detailed information about using our products in context. My presentation on Low Latency Microservices may also help.
Once you have found a product you are interested in, you can read the README for those products
For example if you click Chronicle Queue you can see links on getting started and the documentation on the right.
If you get stuck, you can ask questions on our Google Group and if you find a issue, please let us know via the Issue tab on GitHub for each project.