JRuby is Ruby for the JVM, right? But what does that really mean? What do you get out of the deal? We'll explore what makes JRuby unique among Ruby implementations, and why the JVM is a Rubyist's dream come true. Using JRuby means you have the best GC, real threads, easy and scalable deployment, high performance, no-compile cross-platform libraries, and the best monitoring and profiling tools of any VM. And you get it all without leaving Ruby behind. If you're not using JRuby already, this talk will convince you to give it a try.