Serves a file with syntax highlighting.

# config.ru
require 'rack/source'

run Rack::Source.new('path/to/file')

You can force the language if it isn't automatically detected:

run Rack::Source.new(__FILE__, :lexer => :ruby)

All parameters are passed through to Pygments, so look there for additional options and supported lexers.

If you're using a newer version of Ruby, you'll need to run a thin server instead. There is an issue with Pygments.