Free Software for Scala
Play Framework
A framework designed to make it easy to build web applications with Java & Scala. The Play Framework is is based on a lightweight, stateless, web-friendly architecture that follows a model-view-controller (MVC) pattern. While providing predictable and minimal resource consumption (CPU, memory, threads) suitable for highly-scalable applications. Play is written in Scala and can be used for all programming languages that can be compiled into JVM bytecode.
Scalatra
Scalatra is a simple, accessible and free web micro-framework. It combines the power of the JVM with the beauty and brevity of Scala, helping you quickly build high-performance web sites and APIs.