I often reverse engineer minified javascript/css bundles and deobfuscate them. This little ruby script converts sourcemap files into source files.
[ruby] gyaku.rb <sourcemap-file-path> [<destination>]
It works with both local files and urls. If destination is not specified it dumps everything into a folder named gyaku-bin in cwd.
jsnice works well for javascript. You can simply pretty print css.
MIT