GraalVM is a bunch of components, but the most important one are 1) Graal, a library in Java that is a code generator and optimizer for compiler authors, 2) Nat

GraalVM is a bunch of components, but the most important one are 1) Graal, a library in Java that is a code generator and optimizer for compiler authors, 2) Native Image, a tool which turns Java programs into native executables via Graal, and 3) Truffle, a tool for implementing languages in Java that then get code generated, again by Graal "GraalVM" is the umbrella name of all these things packaged together, together with a couple languages implemented in Truffle. That's what you download when you go to the website. Galahad is a proposal to merge the Graal code generator library in Java, into OpenJDK's codebase, so that it is developed in tandem and comes with first-class support. And none of the other things, for now (Native Image will come later.) But you can also do this today: you can instead configure a stable LTS release of Java to use Graal as the code generator for the HotSpot VM, as an alternative to C2. It's a little bit of work to do so, but you can use any compliant OpenJDK build and test it out. Galahad will just make this an "out of the box" option rather than having to get Graal from Maven or whatever. So, you can just test things incrementally and see if Graal gives performance improvements over C2. You don't need to throw out your whole existing JVM, it's mostly just a new maven dependency. That's a much simpler and more targeted change, if you haven't given it a try (mostly by fiddling with some JVM -XX flags, as usual.)