Rouge is an elegant, extendable code highlighter written in pure Ruby.

Rouge supports 72 languages and counting, including Ruby, JavaScript, Swift, Go, C++, and Haskell.

Rouge aims for the highest quality lexing in all its supported languages, even with strange features and odd corner cases.

Rouge themes are 100% compatible with Pygments' stylesheets. No need to remake your theme, and no need to spawn a Python process either. Rouge is made in Ruby

Find more at http://rouge.jneen.net/.