Have you ever wanted to write pure Ruby code and deploy it on a friend's machine, a server, or some computer where you have little control? With Warbler you can pack a fully functioning application into a single file and run the application anywhere there is a JVM. Build micro webapps, background agents, environment monitors, utilities, or desktop applications that can be trivially deployed across a mixed computing environment. Take Ruby where you previously could not, and leave your source code at home at the same time! We'll discuss how Warbler, JRuby and the JVM are combined to make this happen, and show some examples where such a deployment scheme might make sense. Warbler started as a simple tool to package a Rails application into a single file. Soon after 1.0, Warbler was capable of embedding a minimal web server for fully-functional Rails application servers in a single file with compiled, obfuscated code. The 1.3 release available soon will allow bundling of any Ruby application with bin script and a gemspec or Gemfile into an executable.