JRuby 9000 represents the biggest-ever leap forward for JRuby. Not only have we caught up on compatibility (9000 will be 2.2-compatible from release), but we've completely redesigned our JVM-based runtime and have opened our codebase up to the JRuby+Truffle research project from Oracle Labs. The changes we've made will make it easier to keep up with MRI on compatibility and give us the potential to run Ruby as fast as Java or C. The entire Ruby world will change over the next year, and JRuby 9000 will be leading the way. We'll talk about what Ruby's going to look like once JRuby is "over 9000".