It is my favourite Java IDE.

Granted it was a bit shitty around 2003, when it still used mounts points and a virtual workspace concept. It was also a bit sluggish back then.

When they changed the architecture to drop those concepts, base their build systems on top of Ant/Maven and optimize their UI resource usage, it became great.

Not to forget the work started by JRuby team that helped improve the support for dynamic languages, to the point it feels almost like Java.