JRuby: An Introduction and Install Guide
What is JRuby?
JRuby is simply a Java implementation of the Ruby programming language.
Why Should I Use JRuby?
- Leverage both Java and Ruby libraries (gems)
- Use existing Java platform to deploy Ruby or Ruby on Rails applications.
- The ability to call or extend Java classes from Ruby (including Spring-managed Java beans)
- Leverage the non-verbose and more pleasant experience of writing code with Ruby.
How do I Install JRuby?
- Download and install JDK 1.4 or later.
- Download JRuby 1.0
- Unpack the JRuby archive and add
<jruby-dir>/binto yourPATHenvironment variable. - Test your install by typing a command such as
jruby -v.
Further Reading
Although this book isn’t available until September, 2007, it will be the only published book devoted exclusively to JRuby:

“Practical JRuby on Rails Web 2.0 Projects: Bringing Ruby on Rails to Java” (Ola Bini)