You can use the code from these repositories to experiment, test, build, create patches, issue pull requests, etc.
https://github.com/osgi/osgi-test - Project repository hosted on GitHub.
https://github.com/osgi/slf4j-osgi - Project repository hosted on GitHub.
https://github.com/osgi/osgi.enroute - Project repository hosted on GitHub.
https://github.com/osgi/osgi.enroute.site - Project repository hosted on GitHub.
https://github.com/osgi/jakartarest-osgi - Project repository hosted on GitHub.