The complete version of this post is available on the JRuby blog.
(JRuby is an implementation of the Ruby programming language atop the Java virtual machine, bringing true parallelism, increased performance, and world-class GC to the Ruby world.)
JRuby 9000 is the ninth major release of JRuby. We opted to go with 9000 as a code name and 188.8.131.52 as a version number to separate it from Ruby's version numbers (1.8, 1.9, 2.0 etc).
JRuby 9000 represents years of work by dozens of contributors. It is the single largest JRuby release we've ever done.
- Compatibility is now up to Ruby 2.2 specification, a leap forward from JRuby 1.7's compatibility with Ruby 1.9.3. This includes all language and syntax features and many updates to core libraries.
- The execution runtime has been completely rewritten over the past five years, enabling anyone who has taken a college compilers course to contribute help improve JRuby performance.