@evildictaitor: And the JS is compiled to optimized machine code before it runs (so, at install time, not run time). Sure, why would MSHTML, a shared Windows dll, not be used for the things it's designed and optimized to do on Windows? Or, are you suggesting it would be better if you could use Webkit? This doesn't change the fact that your HTML5 application is not running in a web browser. That level of abstraction is unnecessary. These are Windows client apps, not web pages. You stated as much, I know. Restating the facts, is all.