JSONovich is a Firefox extension that pretty-prints and colorizes JSON content. The extension is trigged by MIME types, currently: application/json, text/x-json, and application/sparql-results+json. It uses json.org's json2.js to parse and indent the JSON data, and google-code-prettify's parser and stylesheet to colorize it.
JSONovich is named after Pavement member Bob Nastanovich primarily because he seems like a swell guy.