It is not C in the browser. It is a sort-of-virtual machine in the browsers. Browsers (i.e. Chrome) are already doing this to execute Javascript, for example.

It is not C in the browser. It is a sort-of-virtual machine in the browsers. Browsers (i.e. Chrome) are already doing this to execute Javascript, for example. Webassembly, to put it in a simplified way, allows you to "bypass" the javascript layer and target directly the virtual-machine. And done in a compatible, well-documented way. So you can gain in performance, and flexiblity.