For anyone else, the normal JVM is likely a better choice for now - the tech built in there is very mature and battle tested.
With that said - baking a bunch of GraalVM features into the normal JVM is nothing but good for everyone. Native AOT compilation does have it's uses outside microservices/serverless, and some cross-pollination of VM ideas is a great idea.
For those you may be better with IBM OpenJ9:
https://www.eclipse.org/openj9/
It also integrates with CRIU so you can almost instantly start/stop the JVM:
https://blog.openj9.org/2022/09/26/getting-started-with-open...
As best I can tell, these are the docker images: https://hub.docker.com/_/ibm-semeru-runtimes
$ docker run --rm ibm-semeru-runtimes:open-11-jdk java -version
openjdk version "11.0.17" 2022-10-18
IBM Semeru Runtime Open Edition 11.0.17.0 (build 11.0.17+8)
Eclipse OpenJ9 VM 11.0.17.0 (build openj9-0.35.0, JRE 11 Linux amd64-64-Bit Compressed References 20221031_559 (JIT enabled, AOT enabled)
OpenJ9 - e04a7f6c1
OMR - 85a21674f
JCL - a94c231303 based on jdk-11.0.17+8)So you can get all the operational benefits of the JVM + a nice set of languages to play with along with interopt cross language (python calling java calling ruby calling perl, etc).
Here's the languages they already have.
https://github.com/oracle/graal/blob/master/truffle/docs/Lan...
From what I can tell, the effort to get any particular language running on Graal is non-trivial, leading to that relatively small list of supported languages - most of which seem to be custom dialects in one fashion or another. Perhaps I'm wrong though...
Many of the languages people use in the real world are really large, really old, really hairy and rely heavily on native extensions that poke arbitrary interpreter internals. Truffle at least makes these implementable with higher performance, and the team size needed to get that done isn't infeasible. But implementing a Ruby or Python will never be a five minute job regardless of what tech you use.
While LLVM or WASM support is nice, most modern languages are not compiling to either one by default, and likely means it's not "turn key" to get your system running on Graal anyway.
How long does take to implement a programming language? Well, from hours to years... depending on the language. To make my point; how long would it take to implement a JVM? A JVM is a complex beast, so I would myself guess from years to a decade probably, what if I told you, that Espresso was written in just 6 months by an intern and a seasoned engineer... in just 6 months it was able to Minecraft and even run itself. I assure you there's no magic here, and certainly no blinding talent either; the only reason for this unheard productivity was Graal/Truffle. So, whenever I talk about Espresso I always give all credit to Graal/Truffle, it is a sublime platform for implementing fast languages and runtimes, of which Espresso is just a byproduct.
Just a tiny side note, a basic toy JVM is actually not that hard (without JIT, trivial GC, limited standard lib) from personal experience, of course a performant/having feature parity one is indeed impressive (though I yet to play with Espresso!)
The smallish list of languages is just due to lack of effort, plus lack of immediate benefits — it is not hard to create an alternative language implementation. It is very hard to create one that is 100% drop-in replaceable with the real thing as every sufficiently complex program will depend on implementation quirks as well.
I am still impressed that it can beat V8 handily without extensive further optimization work in the JVM, but it's not that surprising.
"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.)
From GraalVM docs [1] on memory management: "The G1 GC (only available with GraalVM Enterprise Edition) is a multi-threaded GC that is optimized to reduce stop-the-world pauses and therefore improve latency, while achieving high throughput. Currently, G1 can only be used in native images that are built on Linux for AMD64."
[1] https://www.graalvm.org/22.2/reference-manual/native-image/o...
That being said, most of the JVM projects I'm very familiar are written in Clojure, so they may well be outliers compared to Java or other JVM languages.
To my knowledge, cross-compiling "native" Linux and Windows binaries using Java requires duct tape, chewing gum, and warp-packer.[1][2] If there's another way to cross-compile a Java application into a standalone binary for multiple target platforms, do tell!
GraalVM isn't a panacea. For example, GraalVM cannot compile Renjin[3], a pure Java R interpreter, which means switching from Renjin to FastR. Not trivial. Other sinkholes likely lurk that'll only reveal themselves when walking through the weeds.
[0]: https://github.com/DaveJarvis/keenwrite
[1]: https://dave.autonoma.ca/blog/2020/06/29/write-once-build-an...
As far as I can tell Graal does not have cross-compilation ability currently (there is an open issue here: https://github.com/oracle/graal/issues/407)