Unsemantic CSS Framework
This is a fluid grid system for mobile, tablet, and desktop.
Read more here...
This is dual-licensed this under MIT and GPL.
Basically, you can use the code under whichever license you prefer.
http://opensource.org/licenses/mit-license.php
http://www.gnu.org/licenses/gpl.html
(Some open source projects, such as WordPress and Drupal, require GPL.)