JRuby on App EngineFree to get up and running. Everything you need installs as gems. We just released the 0.0.19 google-appengine gem. App Engine's infrastructure can now anticipate the need for more resources and warm up new application instances (in the background) before routing user traffic to them. You can also reserve three instances by purchasing "Always On" for $9 per month. See the 1.4.0 blog post for more
