You can use the code from these repositories to experiment, test, build, create patches, issue pull requests, etc.
https://github.com/eclipse-ee4j/orb - Project repository hosted on GitHub.
https://github.com/eclipse-ee4j/orb-gmbal - Project repository hosted on GitHub.
https://github.com/eclipse-ee4j/orb-gmbal-commons - Project repository hosted on GitHub.
https://github.com/eclipse-ee4j/orb-gmbal-pfl - Project repository hosted on GitHub.