[cromwellian]

Dart the platform is compatible with all JS engines, Dart2JS.

I could rightly claim that DartVM is just a specialized two-stage compiler that kicks in to give a speed boost.

Compatible != portable. In the real world, performance matters. If I deploy my new triple-A game to the Web, and I'm only going to get 60fps on 25% of the browsers, and 15fps on the rest of them, do I really consider it the same ecosystem?

[azakai]

> If I deploy my new triple-A game to the Web, and I'm only going to get 60fps on 25% of the browsers, and 15fps on the rest of them, do I really consider it the same ecosystem?

This was always an issue on the web. Browsers have always had speed differences on that scale - either due to browser optimizations, or running on much weaker hardware (a phone vs. a powerful desktop). We've never had consistency the way consoles do, which is why AAA games run best there.

[TazeTSchnitzel]

> Dart the platform is compatible with all JS engines, Dart2JS.

Not quite. Most of Dart (though not all) can compile to JS, and you can then use the JS version or the Dart version depending on browser support. That doesn't mean existing JS engines can run Dart code, it's just you can choose to fall back to Dart compiled to JS.