***Note:*** *Unfortunately this question was closed, but I&#39;m trying to maintain it for if someone else comes along with the same question.*

I&#39;ve been looking for a good solution to developing a service in Scala that will sit between mobile devices and existing web services.

The current list of viable options are:

 - [Finagle][1]
 - [Spray][2]
 - [BlueEyes][3]
 - [Akka][4]
 - [Play2 Mini][5]
 - [Unfiltered][6]
 - [Lift][7]
 - [Smoke][8]
 - [Scalatra][11]

There are probably more options out there. How does one decide which one to use? What are the traits (excuse the pun ;-) of a good Scala middleware choice. On the one side, I would like to go for Akka, because it is part of the TypeSafe Scala stack, but on the other, something like Finagle has a rich set of libraries and makes plumbing so easy. Spray looks nice and simple to use.

Any advice, insights or experience would be greatly appreciated. I&#39;m sure someone out there must have some experience with some of these that they won&#39;t mind sharing.

**UPDATE:**

I would love for this question to be reopened. A good answer to this question will help new Scalateers to avoid related pitfalls.

**UPDATE 2:**

These are my own experiences since asking this question:

*Finagle* - I used Finagle for a project and it&#39;s rock solid.

*Spray* - In my latest project I&#39;m using Spray and I&#39;m extremely happy. The latest releases are built on Akka 2 and you can run it directly with the Spray-can library which removes the need for a web server. Spray is a set of libraries, rather than a framework and is very modular. The [Learn about Spray: REST on Akka video][9] gives a great overview, and [this blog at Cakesolutions][10] shows a really nice development approach and architecture.

**UPDATE 3:**

Life moves pretty fast. If you don&#39;t stop and look around once in a while, you could miss it. - _Ferris Bueller_

These days the choice has become simpler. In my humble opinion Spray has won the battle. It is being [integrated into Akka][12] to become the next Akka HTTP. I have been using Spray now on multiple projects and can honestly say that it&#39;s fantastic and best supported software I have ever encountered.

This does not answer the initial question, but at least gives some indication on why Spray seems like the best choice in most cases. It is extremely flexible, non-blocking and very stable. It has both client-side and server-side libraries and a great testkit. Also, have a look at these stats to get an idea on performance: [Web Framework Benchmarks][13]

  [1]: http://twitter.github.com/finagle
  [2]: https://github.com/spray
  [3]: https://github.com/jdegoes/blueeyes
  [4]: http://akka.io/
  [5]: https://github.com/typesafehub/play2-mini/
  [6]: http://unfiltered.databinder.net/Unfiltered.html
  [7]: http://liftweb.net/
  [8]: https://github.com/mDialog/smoke
  [9]: http://marakana.com/s/spray_rest_on_akka_from_the_northeast_scala_symposium,1150/index.html
  [10]: http://www.cakesolutions.net/teamblogs/2012/07/29/api-first-rest-in-akka-and-spray/
  [11]: http://www.scalatra.org/
  [12]: http://typesafe.com/blog/typesafe-gets-sprayed
  [13]: http://www.techempower.com/benchmarks/#section=data-r7&amp;hw=i7&amp;test=json

All Spray Solutions on Gang of Coders

Total of 1 Spray Solutions

What are the differences between Scala middleware choices?