Embedded HTTP servers with Scala

Recently I was looking for an embedded HTTP server I can use from Scala app. Surprisingly there are not much information on the web and most of it is outdated.  The best one I found is this question on StackOverflow.
Here is some summary of what I found:

  1. Jetty – is tone of the easiest ways to start and well known to Java developers.
  2. Scalatra – very nice framework, lot’s of options, easy to use.
  3. Spray – looks like a very cool project but way to complicated for Scala beginners.
  4. http4s – another promising interface for HTTPs