Introduction to JRuby

This document provides an introduction to JRuby, which is a Ruby interpreter rewritten in Java. It discusses motivations for using JRuby such as accessing Java libraries from Ruby and vice versa. It covers key aspects of JRuby including running Ruby code on the Java Virtual Machine, interacting with Java classes from Ruby, and inheriting from Java classes. It also benchmarks JRuby performance and outlines future directions. The document is intended to explain what JRuby is and why developers might want to use it.