LLVM to JS
The escape() method does not encode the + character which is interpreted as a space on the server side as well as generated by forms with spaces in their fields.
Highlight.js highlights syntax in code examples on blogs, forums and in fact on any web pages. It's very easy to use because it works automatically: finds blocks of code, detects a language, highlights it. This is not only convenient but also allows highlighting for code examples marked up with writing syntaxes like Markdown where there is no way to specify HTML class easily.