Over at CSS Tricks, there was a poll in 2012 on CSS preprocessors and LESS was the most popular. With CSS preprocessors, the ones that support CSS syntax are more popular since you can reuse existing CSS code and copy from examples and tutorials. However, the story is different with JavaScript preprocessors. Sites like js2coffee and even FiddleSalad under the “Tools” menu supports converting CoffeeScript to JavaScript. In addition, programmers prefer clean, easy to read languages.
I checked Google trends for the search volume of the languages with unambiguous names, and it looks like TypeScript is starting to pick up popularity despite the lack of documentation.

Beware that prior to 2004, markdown didn’t exist as well as many of the other languages. The search volume came from other usages of the words.