Project Valhalla and the projects that comprise it are still in design stages, but we are getting closer. Current activity indicates it won’t be long before value classes drop in a JDK preview.

Version 24 version introduces several new language features which collectively simplify code, and provide powerful tools for bytecode manipulation and advanced stream processing.

In Java 24, Project Leyden’s JEP 483, "Ahead-of-Time Class Loading & Linking", starts Java applications like Spring PetClinic up to 40% faster without code changes or new application constraints ...