Rainbow is a lightweight syntax highlighter implemented in JavaScript.

I have added support for the R language and ported the pastie theme (with a few minor differences) from Pygments to Rainbow. These changes have been incorporated by Craig Campbell in the canonical Rainbow repository .

Due to the limitations of JavaScript’s implementation of regular expressions, highlighting R output (like you would see in an R session, with prompts) is more challenging and thus was not attempted.

Try highlighting some R code for yourself! Enter code into the text area below, and momentarily the highlighted code will appear below.