Dart is a significant deviation and expected to support debugging directly in the language. This can be done for CoffeeScript et al too - efforts are already u

Dart is a significant deviation and expected to support debugging directly in the language. This can be done for CoffeeScript et al too - efforts are already underway. Also, the VM wouldn't be required, it would just provide performance improvements. There's just too much embrace-extend-extinguish risk for anyone but Google in that. That's why Mozilla and Microsoft are burning it at the stake.