Dart Editor
dartlang.org
dartlang.org
I imagine the Dart editor was probably spun off early attempts at writing Eclipse integration, until someone realized they could write a much leaner editor and gain some developer props for focusing on the developer experience first.
Instead, they released Eclipse RCP application that people are not even going to bother to install, let alone play with it. Even Eclipse plugin would be better.
Also, what's the over under on when Dart becomes a first class language in Chrome?