I\'m reading JEP 317. It says that Graal (a new experimental Java-based JIT compiler) will be part of JDK 10, but then it says that is already available in JDK 9. So, what\'
Graal is included in 9 but it used in a different way.
In Java 9 Graal is used as an AOT(Ahead of time) compiler which allows users to use the jaotc tool to create manually compiled .so libraries.
These libraries can then be loaded at JVM startup and directly used.
A detailed description can be found at the related Java 9 JEP: http://openjdk.java.net/jeps/295
In Java 10 Graal, as described in JEP 317, can be used as the JIT compiler instead of HotSpot.
This means that classes will be compiled in the JVM "on the fly" instead of requiring manual compilation beforehand.