With version 0.42 of the Eclipse OpenJ9, there is support for OpenJDK 21 features. Various JDK 21 features are now supported such as virtual threads, scoped values, record patterns, the latest foreign function and memory API, the incubator incarnation of the Vector API, and more. OpenJDK 21 debuted back in September with many notable changes and it's also the latest Long Term Support release after OpenJDK 17.
Eclipse OpenJ9 0.42 also drops the jextract dump extractor tool since it's been replaced by the jpackcore tool, changes to the system garbage collector behavior, and various other changes.
Downloads and more details on the open-source OpenJ9 v0.42 JVM release via GitHub .