IntelliJ IDEA is now Open Source!

Wow, my favorite Java IDE - IntelliJ is now Open Source. It has to be because of intense competition and widespread adoption of Eclipse and to some extent NetBean's Groovy and JVM other language support.

Even though they are miles apart from IntelliJ, I guess "free" is a price that is very hard to compete with.

Scala and Groovy are going to lead the next wave, if you will, in JVM Languages. Even if they manage to build a sizable Developer community (not users, but contributors) around IntelliJ that can match Eclipse, which is quite unlikely; I wonder why they did it and how do they intend to make any money?

I know that their .Net IDE - ReSharper is way better than Visual Studio. I suppose that is their only remaining cash cow now. Who knows?