is implementation of code from twitter brothers and Magento e-Commerce platform.
When you connect, merge, mix or play with those 2 products, you get Magento Responsive theme aka BOOTSTRAPPED.
Check out some action, do not hesitate to make test orders
http://bootstrapped.magenthon.com
or
You can preview how responsive is.
Download whole content and put in your public_html folder of Magento installation.
Navigate to design configuration in Magento admin panel and for theme package type "bootstrapped".
Keep up to date by following Magento Marathon, @magenthon.
Read more detailed on Magento Marathon Blog.
Vedran Subotic