I've enrolled on Functional Programming Principles in Scala class at Coursera and it seems the official IDE for the class is Eclipse. However, I started to hate it only after a few hours of using it because it kept freezing and I had to force quit it over and over.

Since I am a fan of Jetbrains IDEs (I use both RubyMine and PhpStorm) I wanted to give IntelliJ a shot. Fortunately, IntelliJ Community Edition, which is free, supports Scala through a plugin, but it was a little tricky for a beginner to see my first Scala "Hello, World!" running. Thanks for the FP class forum members, I could finally figured out how to do. Here I would like to share.

Install Scala and SBT

$ brew install scala
$ brew install sbt

Setting up IntelliJ for a Scala sbt project

The instruction below is copied from a FP class forum thread and is extremely useful.

1. Download IntelliJ 11.1.3 from http://www.jetbrains.com/idea/
2. Install the latest scala plugin from the plugins manager dialog. Also make sure to go into Project Structure and select your JDK.
3. Add the following lines to /project/plugins.sbt
   

   addSbtPlugin("com.github.mpeltonen" % "sbt-idea" % "1.1.0")

4. Build the project files for Idea:
   

   $ cd <PROJECT_DIR>
   $ sbt gen-idea

5. open up IntelliJ and do Open Project and open the top level directory
6. Click the yellow [ T ] box in the lower right corner to turn on type-aware highlighting for scala.

 References

1. Functional Programming Principles in Scala: Setting up IntelliJ from the Guardian's developer blog
2. https://github.com/mpeltonen/sbt-idea
3. https://class.coursera.org/progfun-2012-001/forum/thread?thread_id=54 see Dhananjay Ragade's comment.