There's a few more: * Padrino (http://padrinorb.com http://padrinorb.com) built on top of Sinatra * Volt (http://voltframework.com http://voltframework.com) w

There's a few more: * Padrino (http://padrinorb.com http://padrinorb.com) built on top of Sinatra * Volt (http://voltframework.com http://voltframework.com) which allows you to write Ruby both in the backend and front-end * Cuba (http://cuba.is http://cuba.is) is a web microframework * Roda (http://roda.jeremyevans.net http://roda.jeremyevans.net) is also a microframework (both Cuba and Roda are like toolkits with very basic cored and a bunch of plugins distributed together with the framework)