This extension adds an item to the right-click menu that lets you force a link to open as a particular media type (or MIME, if you're old-fashioned).
Why? Here's why: hello_world.rb
Chrome doesn't recognize the media-type application/ruby, so it downloads the
file rather than displaying it. Grr.
With this extension, you can right-click on the link and choose to open it as
text/plain. It works by intercepting the HTTP headers of the response and
replacing the content-type definition.
You can build it yourself, or install it directly from the Chrome Web Store.
NOTE: This extension requires Chrome 18 or better. Currently (13 Jan 2012) this requires being subscribed to the dev channel.