Ruby Under a Microscope

Chapter 10. JRuby: Ruby on the JVM

JRuby is Ruby implemented on the Java platform.

In Chapter 1 through Chapter 9 we learned how the standard version of Ruby works internally. Because Ruby is written in C, its standard implementation is often known as CRuby. It’s also often referred to as Matz’s Ruby Interpreter (MRI), after Yukihiro Matsumoto, who created the language in the early 1990s.

In this chapter we’ll see an alternative implementation of Ruby called JRuby. JRuby is Ruby implemented in Java instead of C. The use of Java allows Ruby applications to run like any other Java program, using the Java Virtual Machine (JVM). It also allows your Ruby ...