Exporting Applications
Ruby-Processing can export Mac/Windows/Linux applications:
rp5 app path/to/my_sketch.rb
It will pack up your app, its data folder, all of the libraries that it's loading, and tuck them into a brand-new MySketch.app, ready to share. If you happen to have a .icns icon file in your data folder, it will use that for the icon of your application (for Macs). Now you can distribute the application without any need to install JRuby or Ruby-Processing.
For Windows and Linux, the .app acts as a folder containing executable programs. You can rename it or share it as is (one caveat is that any custom ruby-libraries need be to wrapped in an eponymous folder, as per the original library, and not nested see vecmath library).
Illustration below almost certainly won't work since oracle jdk8, you can help fix it as a Mac user we need an new application bundler, along these lines.
A Ruby-Processing application, running in the Dock
Check out the Gallery to grab some application examples.