This last quarter I'm focused in Principles of Reactive Programming with Scala taught by Martin Odersky, Erik Meijer and Roland Kuhn at Coursera.
As IDE they suggest to use ScalaIDE, a powerful IDE based on Eclipse that, among other things, allows you to use an interactive worksheet (as a REPL) where to practice with objects, functions and all the stuff.
My problem is that I'm a IntelliJ IDEA developer (sorry, we all have our defects ;-) ), so I've tried to import each week assignments to IntelliJ. After several attempts, I've found this sbt plugin gen-idea.
In order to install, you have to create (if it doesn't exist) plugins.sbt file in project folder and add following line:
addSbtPlugin("com.github.mpeltonen" % "sbt-idea" % "1.5.2")
Once done this, you invoke plugin with:
sbt gen-idea
and just wait while it downloads the whole internet twice and generate .iml and .idea files. Then, you have to open files with IntelliJ.
As an aside, I'm using Scala Plugin for IntelliJ IDEA, which includes a worksheet as well. So far, so good.