Listly by John A. Goes
A list of Scala web frameworks designed specifically for the development of RESTful APIs (i.e. web services that embrace the machinery and language of HTTP). Excluded are larger, general-purpose frameworks which support REST only tangentially.
A lightweight Web 3.0 framework for Scala, featuring a purely asynchronous architecture, high performance, scalability, and usability, and a functional, composable design built on the strengths of Scala.
Tiny Scala web framework, inspired by Sinatra.
A toolkit for servicing HTTP requests in Scala. Unfiltered embraces the HTTP protocol, Scala, type-safety, and minimalism.
Bowler is a RESTful, multi-channel ready web framework in Scala with a functional flavour.
spray is a suite of lightweight Scala libraries for building and consuming RESTful web services on top of Akka.
Lift is the most powerful, most secure web framework available today.