If you're not using a responsive framework to develop websites you should seriously consider changing course this year. Using a pre-built framework can save you time, help you avoid errors, and lead to a more thorough and better developed site.
ZURB has been designing products since 1998 and Foundation is their answer to advanced responsive front-end development. It's easy to learn and quick to grasp. We use this framework for the bulk of our client projects.
Bootstrap is one of the most popular front-end frameworks and originally created by a developer at Twitter in 2010. It contains HTML, CSS, and Javascript elements to rapidly create rich user experiences. We've used this for a few custom applications because of its thorough, pre-built capabilities.
Skeleton is about as simple as it gets. It is a bare bones responsive framework intended for smaller projects or for those that want a non-stuffy starting point. I've used this on a handful of sites - mostly where I'm creating a simple website with only a handful of pages.
There are many other responsive frameworks from which to choose. These are just the three that we have used and recommend. They're worth taking a little time to learn because each can have a nice cozy place in your web development arsenal.
