Downloading GraalVM

JRuby+Truffle is designed to be run with a JVM that has the Graal compiler. The easiest way to get this is via the GraalVM, available from the Oracle Technology Network. You can get either the runtime environment (RE) or development kit (DK).

http://www.oracle.com/technetwork/oracle-labs/program-languages/

The GraalVM actually already includes JRuby+Truffle, as a ruby command, but this isn't always the latest version so we can also use it to run a version of JRuby+Truffle built from source or installed by any other method used to get JRuby.

To use GraalVM to run JRuby+Truffle, set the JAVACMD environment variable.

$ JAVACMD=graalvm-0.16-re/bin/java bin/jruby.bash -X+T ...