I wonder what happened with the Eclipse OpenJ9 project: https://www.eclipse.org/openj9/

It has build instructions on the site, but not pre-built binaries for download. In the site that you linked, however, it says that Semeru does use it under the hood.

I actually recall it being one of the options from AdoptOpenJDK instead of HotSpot: https://adoptopenjdk.net/releases.html?variant=openjdk8&jvmV...

But the Temurin releases from Adoptium no longer have that option, which is curious: https://adoptium.net/temurin/archive/

Oh well, it seemed like a cool project, like an attempt at adapting JDK for cloud workloads and smaller services, without going as far as GraalVM.