When Lars Bak and Kasper Lund launched Dart [2], I found it sad that they weren't more bold - left CSS and the DOM alone, and created an alternative Content-Type. So you can choose to Accept 'application/magic-bytecode' [3] before text/html, if your client supports so. Sadly, we ended up with Web Assembly, which by the few talks I've seen, appears to only cater to that of graphic/game developers, with no support for dynamic or OO languages.
[1] https://www.youtube.com/watch?v=FvmTSpJU-Xc [2] https://www.dartlang.org [3] Or in Dart lingo, a VM snapshot.