Using Scala Futures to reimplement the Java Future examples used to provide the motivation for Netflix RxJava - https://gist.github.com/benjchristensen/4671081#file-futuresb-java-L163 - in the announcement: http://techblog.netflix.com/2013/02/rxjava-netflix-api.html The code compares quite nicely with RxJava

gistfile1.scala

@RunWith(classOf[JUnitRunner])
class Example1Test extends FunSuite with ShouldMatchers {

  // Services that return Futures

  def serviceA() = Future { 7  }
  def serviceC(x : Int) = Future {  2 * x }
  def serviceB() = Future { 9}
  def serviceD(x : Int) = Future { 5 * x}
  def serviceE(x : Int) = Future { 4 * x}

  test("using flatMap and map") {
    val f1 = serviceA()
    val f3 = f1.flatMap{ serviceC }
    val f2 = serviceB()
    val f4 = f2.flatMap{serviceD }
    val f5 = f2.flatMap{serviceE }

    val z0 = (f3 zip f4 zip f5) map { x => (x._1._1, x._1._2, x._2)}
    val z =  Await.result(z0, 10 second)

    z should equal((14,45,36))
  }
  
  test("call many services with futures and map()") {
    def doMoreWork(x : Int) = x * x

    val f1s = (1 to 10).map(serviceC)
    val f2s = f1s map { _.map(doMoreWork) }
    val f3 = Future.sequence(f2s)
    val r  = Await.result(f3, 1 seconds)

    r should equal(List(4, 16, 36, 64, 100, 144, 196, 256, 324, 400))
  }


}