Graal Project

a quest for the JVM to leverage its own J


The Graal OpenJDK project grew out of the Maxine VM project. In the context of the Maxine VM, Graal demonstrated that a compiler written in Java (with all its software engineering advantages) could generate highly optimized code without compromising on compile times.

Graal was then spun off as an OpenJDK project in 2012 to bring these properties to HotSpot.

This goal has been achieved as evidenced by the inclusion of the Graal compiler in JDK 9 as the basis for jaotc and in JDK 10 as an experimental tier 4 just-in-time compiler. To use the latter, simply add these VM options to the java command line:

-XX:+UnlockExperimentalVMOptions -XX:+UseJVMCICompiler

Further work on integrating Graal in the OpenJDK has moved to Project Metropolis.

Development of GraalVM technologies independent of OpenJDK can be found at and Information for staying connected with the GraalVM community can be found at

This Project is sponsored by the HotSpot Group.