NetBeans 6.0 is already becoming a great Ruby on Rails IDE. However, with all the extra Java stuff it can be a bit slow and cluttered if you only develop in Ruby. Tonight I discovered the NetBeans team has created a Ruby Only NetBeans IDE. The IDE comes pre-installed with all the Ruby on Rails stuff. The project looks rather new and still very beta. However, I actually found this version of NetBeans to be more stable then the bloated Java/Ruby NetBeans 6.0 builds. So give it a try and let me know you you think. Hopefully, the continue work on this project and release it as a actually product some day.