What's really nice about the compiler being in JavaScript is that you can run JavaScript anywhere: in the browser, on any OS, embedded in any major web framework. If the compiler were written in any other language, you'd have to worry about dependencies.
This applies to HTML and CSS preprocessors as well: I'd advocate Jade over Haml and Stylus or Less over Sass, simply because Jade and Stylus/Less aren't tied to the Ruby ecosystem. JS is the real deal for "Write Once, Run Anywhere."
This applies to HTML and CSS preprocessors as well: I'd advocate Jade over Haml and Stylus or Less over Sass, simply because Jade and Stylus/Less aren't tied to the Ruby ecosystem. JS is the real deal for "Write Once, Run Anywhere."