FTA:<p>> We are still using MRI 2.0.0-p195 on Heroku and haven’t switched to either JRuby or Rubinius. Although there is a lot performance we could gain from this switch we are happy with the performance we have and it would make our development more complicated.<p>From the Rubinius 2.0 release post[1]:<p>> Evan created Puma to meet the need for a fast web server that would promote the Rubinius parallel thread support. Puma also works well on MRI and JRuby. It provides Ruby applications excellent performance and multi-core scaling, especially when there's no global interpreter lock.<p>I'm very interested to see how much performance they would gain by switching to Rubinius, and why they say it would complicate their development.<p>[1] <a href="http://rubini.us/2013/10/04/rubinius-2-0-released/" rel="nofollow">http://rubini.us/2013/10/04/rubinius-2-0-released/</a>
Shameless plug: I've been moving over my own apps to Puma lately and definitely noticed improvements in performance without switching VM (we've used MRI so far). Lately, even did a small blog post on the topic:<p><a href="http://jasdeep.ca/2013/07/deploying-rails-apps-with-puma-and-nginx/" rel="nofollow">http://jasdeep.ca/2013/07/deploying-rails-apps-with-puma-and...</a><p>This should get you started on non-Heroku platforms with Puma & Rails, well for development & staging purposes. I still have to do a post on setting up Puma for actual production deployments.