Egor Malyshev :

I believe you’ll like this announcement — IntelliJ IDEA has just gone open-source! Check out the press release as well as the new jetbrains.org community site for the details. We all will soon get a lot of new friends and colleagues in our IntelliJ IDEA community!

http://blogs.jetbrains.com/idea/2009/10/intellij-idea-open-sourced/

http://www.jetbrains.org/