Because it is a Google project, and other browser vendors (those mentioned in Eich's next sentence) don't want to include something from a competitor into their

Because it is a Google project, and other browser vendors (those mentioned in Eich's next sentence) don't want to include something from a competitor into their own browser. It'd be about like Ford proposing that GM and Dodge install Ford's GPS unit (hopefully you can relate to major US automakers). He might have spoken too soon though (or I missed the point), as there are projects out now that I think could very well make a decent runtime for Dart. Using tech such as asm.js[1] -- which Firefox now includes natively (drawing a parallel to Google's Dart) -- along with new versions of JS, and modern JS browser optimizations....it can make for a very efficient script. As efficient as Dart with the VM? Probably not, but I'm not sure just how much of the market you're going to corner by such an advantage. Any JS outside of a browser will undoubtedly run on NodeJS, which is going to be more efficient than Dart for most (if not all) tasks, and so it just comes to down to in-browser usage. For 99.99% of current web apps, I don't think you'd never notice a difference. 1. http://en.wikipedia.org/wiki/Asm.js http://en.wikipedia.org/wiki/Asm.js