ZURB Foundation Framework
A recent article over at Web Monkey highlights the release of ZURB Foundation framework version 4. ZURB Foundation framework works similar to Bootstrap framework. It provides HTML and CSS building blocks that you can use to build a responsive web site, right from the start. Version 4 uses a new foundation that utilizes mobile first approach.
There are three ways you can try out Foundation 4. You can download the straight compressed CSS and use that as a starting point for your own customizations. Alternately you can customize your build of Foundation, including only the elements you need; or you can install the SASS version of Foundation and customize it within your SASS code.
Source: Web Monkey
It is definitely worth a look if you still have not found a Responsive Website framework that you like. It is very popular on GitHub, making it to the top 20 most starred projects.