To give this the context that the moderators removed when they changed the title, Graal is a new dynamic compiler (JIT compiler) for the JVM from Oracle Labs. It's used, in amongst other projects, as the compiler that backs the high performance implementation of Ruby and C extensions, JRuby+Truffle.
I just want to say you are one of those rockstar programmers right now. I was talking today with a co-worker about JRuby and your research, and even he was impressed.
I am just starting to get back into programming, and because I need credit coursework I have to start off with Java this time. 1yr to 6m ago, I was dreading that prospect. But your work, other JVM languages like Clojure, and the undefeatable power of JVM web stacks on things like Tech Empower benchmarks make the uphill battle to understand Java so long, but seem so much more fruitful than when I would look at Java prior before I read so much cool Java research and practice on HN, Reddit, and elsewhere in that time.
So thanks for your work. I one day hope to understand at least 1% of Java internals and understand your Graal and Truffle work.
http://www.chrisseaton.com/rubytruffle/