Intro to J Ruby

This document provides an overview of JRuby, which is a Ruby implementation that runs on the Java Virtual Machine (JVM). It discusses key aspects of JRuby like its compatibility with Ruby, access to Java libraries, integration with Java code, and usage in applications like Rails. Specific topics covered include JRuby fundamentals, dynamic typing, classes and modules, mixins, Java integration features, testing Java code from Ruby, and calling Ruby from Java using JSR-223.