It's very easy to use library for highlighting code blocks like HTML or CSS files from GitHub repositories that contain them (e g., markdown). I didn't find any other features so far which could be interesting enought if compared against free versions such as highlightr - but maybe they're existent :) Also it doesn´s support many languages at once unlike Pygments-based libraries do! And also its license isn;' open source :-( But still i'm using this lib even though there are better alternatives out than just because their API fits my needs perfectly well without me having too much problems integrating it into existing projects written by others ;).