Metropolis project status

vladimir.kozlov at vladimir.kozlov at
Wed Jun 23 19:44:01 UTC 2021

Metropolis project is put on hold.

The last update was Early Access build based on JDK 15 [1]. It uses natively (AOT) compiled Graal JIT compiler.

We still think "Java-on-Java" is right direction for some components of HotSpot VM. We may return to work on them later. 
We learned a lot and made some progress with Graal as JIT in Metropolis. And we got very good experience from AOT work 
which will help us with Project Leyden.

About Graal and AOT compilers status in JDK.

After few years working on them we decided to remove them from JDK [2]. We have seen little use of these experimental 
features since they were introduced. And the effort required to maintain and enhance them is significant.

Developers who wish to test the Graal compiler for either AOT or JIT compilation should use GraalVM [3].

Vladimir K


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