Akka with skinny-framework. Combined skinny-framework's boilerplate and Scalatra's akka example. http://scalatra.org/2.2/guides/async/akka.html

RootController.scala

package controller

import akka.actor.ActorSystem
import scala.concurrent.{Promise, ExecutionContext}
import org.scalatra.{AsyncResult, FutureSupport}
import dispatch._
import skinny.controller.SkinnyServlet

object DispatchAkka {
  def retrievePage()(implicit cxt: ExecutionContext): Future[String] = {
    val prom = Promise[String]()
    dispatch.Http(url("http://slashdot.org/") OK as.String) onComplete {
      case r => prom.complete(r)
    }
    prom.future
  }
}

class RootController extends SkinnyServlet with FutureSupport {
  protected implicit def executor: ExecutionContext = {
    val system: ActorSystem = this.servletContext.getAttribute("ActorSystem").asInstanceOf[ActorSystem]
    system.dispatcher
  }

  def index = {
    contentType = "text/html"
    new AsyncResult { val is =
      DispatchAkka.retrievePage()
    }
  }

}

ScalatraBootstrap.scala

import _root_.akka.actor.{ ActorSystem, Props }
import skinny._
import skinny.controller._
import _root_.controller._

class ScalatraBootstrap extends SkinnyLifeCycle {
  val system = ActorSystem()

  override def initSkinnyApp(ctx: ServletContext) {
    ctx.setAttribute("ActorSystem", system)
    Controllers.root.mount(ctx)
    AssetsController.mount(ctx)
  }
  
  override def destroy(ctx: ServletContext) {
    system.shutdown()
    super.destroy(ctx)
  }

}