JRuby allows developers to use the Ruby programming language on the Java Virtual Machine. It provides a solid, reliable implementation of Ruby that integrates well with existing Java libraries and tools. JRuby brings the features of Ruby like its elegant syntax to Java developers, while also bringing the large Java ecosystem to Ruby developers. It allows both communities to work together on the same platform.

1. JRuby is Awesome
a.k.a Pump It Up: Maximizing the Value of an Existing
Investment in Java with Ruby

2. Me
• Charles Oliver Nutter (“headius”)
• JRuby Guy
• JVM Languages Guy
• Ex-Sun Guy
• Engine Yard Guy

3. You
• Java developers?
• Let’s call ourselves JVM developers now.
• Other languages?
• Other platforms?

4. Why JVM?
• Inertia
• Wealth of libraries
• Widely accepted
• Momentum is coming back
• Awesome VM, best platform

5. Why Not JVM?
• Alternative languages?
• Cumbersome standards?
• New shiny? Cool factor?
• Tooling woes?
• Native library/OS features?

6. What If?

7. JRuby
• Ruby language on the JVM
• Solid, reliable implementation
• Production users: finance, gov’t, infrastruct
• Integrates well with JVM langs, libs
• Deploys on Java servers
• Large, active community

8. Language
• Ruby is a beautiful, fun language
• A standard by which others are judged
• Wealth of books, resources, conferences
• Healthy, growing community
• JRuby brings Ruby to Java and Java to Ruby
• Part of the family!

9. A Taste of Ruby

10. Java, of Course
• Call Java libraries
• ...and decorate them
• Impl interfaces, extend classes
• Die, CLASSPATH, die!
• Fixing JDK issues (JDBC unloading...)

11. Java Integration

12. Tooling
• Unit testing: test/unit
• Spec/behavior-driven: rspec
• Build, automation: rake
• Packaging: rubygems

13. Tooling

14. Web Development
• Full-size apps: Rails
• Services, micro apps: Sinatra
• Deployment:
• Command-line servers like Trinidad
• WAR deployment with Warbler

15. Web Dev

16. Native Access
• Better process, filesystem, IO
• Process control
• Symlinks, globbing
• Easy non-blocking IO
• FFI for binding any native library

17. Native Access

18. Other Targets
• Engine Yard AppCloud
• Google AppEngine
• Amazon Elastic BeanStalk
• Android

19. What Next?
• www.jruby.org
• Book: “Using JRuby” from Pragmatic
• Conferences near your home town
• Inexpensive and fun
• User groups, mailing lists
• www.engineyard.com/jruby

20. Thank You!