BitNami JRubyStack makes JRuby on Rails setup simple
BitNami JRubyStack makes JRuby on Rails setup simple. The stack comes bundled with JRuby, Rails, Tomcat, Glassfish Gem, Mysql and Subversion. You can run your Rails app either with Glassfish or make a war and deloy to tomcat. The whole package is distributed under Apache 2.0 License.
There has been few sites that use JRuby proving that JRuby does scale. Thoughtworks project management application mingle is powered by JRuby and Rails. Sun mediacast site is also now running on JRuby and Rails