According to https://patents.google.com/patent/US6842759 this seems possible with the JVM.
My question would be, which JVM implementation (IBM, Oracle, or something else) can do sharing of Java Objects off-heap or across multiple processes?
EDIT:
I am not referring to interprocess communication (IPC) nor caching (e.g. using EHCache or ChronicleMap, etc.), like sharing serialized data structures but, I mean instances of Java classes from one process to another.