Tony

Tony is a proof of concept demonstrating the absolute minimum necessary to build responsive Drupal themes from the ground up with a custom layout and break points for display on all sizes.

Like Core's Stark theme, Tony consists only of a .info file and a layout.css file (along with the .sass source file used to generate it). This theme is called Tony in tribute to my favorite Stark (and for the nerds).

You can read much more about it in the blog post.