CSS Cement is a CSS/HTML only Framnework built using LESS.
It is completely responsive allowing you to set the minimum and maximum width of your site. You can select from a range of grid sizes and even switch part way through you page.
The framework is highly configurable with hundreds of different variables.
The framework includes lots of optional modules that need only be compiled if needed.
To see a demo and sample code visit http://rachelreveley.co.uk/css-cement/