Scalatra is yet another microframework for web development that combines powerful features of the Java Virtual Machine with the brevity-driven development of Scala. The result is a tool that can help you build websites and APIs quickly. Besides, it serves as a great server-side counterpart for in-browser frameworks such as Ember or Angular. 

Scalatra is a free and open source web application framework written in Scala. It is a port of the Sinatra framework written in Ruby.