Do we use Eclipse IDE with Eclipse OpenJ9 JVM? If yes, which one is recommended to be used with Eclipse IDE, HotSpot or Eclipse Open J9. Any benchmarking we have ever done for Eclipse IDE with both JVMs?
So overall, the state of Platform running on OpenJ9 is that it's expected to work but not tested.
Most Eclipse EPP packages do come with JustJ 15, which embeds OpenJDK 15. And those are tested by their maintainers and are released to the ~4 million users of Eclipse IDE.
Being allowed to embed a Java Runtime was a legal challenge and the result is that only last release of OpenJDK is allowed to be distributed at the time of the release. As long as this doesn't change, there is no big value for the Eclipse IDE to try OpenJ9.
However, from a RCP product perspective, OpenJ9 could be a good choice and could be worth it. I'm not aware of some Platform committer who has done actual benchmark, but it would be good to know if someone has done/will do.
If some organization has interested in seeing OpenJ9 better tested, they should get in touch with the PMC and build an agreement on how to do that. I imagine that an organization that can support the project with additional resource packs ( https://wiki.eclipse.org/CBI#Additional_Resource_Packs
) to add test targets without slowing down the project builds and some maintainer to take care of related releng work would be totally welcome.