Thank you for your interest in contributing to the Apache Solr project. Solr continues to improve via the many contributions of developers around the world and new contributions are welcomed and encouraged.
Your suggestions and comments can be made directly through the Apache Solr JIRA.
There are many ways to participate in and contribute to Solr, such as: code implementation, test implementation, documentation improvements.
If you have any questions along the way, you can reach out to the community using the resources provided here.
Information on how to contribute can be found in the How To Contribute developer documentation.
One very helpful area for contribution to Solr is via documentation improvements and additions to help make Solr easier to use for others. You can read more about how to modify and update Solr documentation in the Solr Reference Guide README.
Additionally, you can contribute to improve the Solr developer documentation to make the contribution process easier for future developers.
Finally, changes to the Solr website (solr.apache.org) can be made in the solr-site repository.
Information on how to work with Solr source code and the build system can be found in the Solr Source Code developer documentation.
Information on IDE support can be found in the IDEs developer documentation.
Information on JVMs can be found in the JVMs developer documentation.
Frequently asked questions can be found in the FAQ developer documentation
Even more hits and tips are to be found in the Solr Wiki.