Bootstrap is without a doubt the most widely used front-end framework, it's thought to power 1% of all websites currently on the web and if we look at how Bootstrap is built it's easy to see why, it simply makes development so much easier for us. Now the RC2 of Bootstrap 3 is out and they have completely redone the framework from top to bottom. Let's now see what has changed to help your migration a little. The grid ... The grid is one of the biggest changes and has been completely rebuilt for a mobile-first approach...