Mueller is a modular grid system based on compass that enables you have full control over column width, gutter width, baseline grid and media-queries. It can be used for responsive and non–responsive layouts as well.
The mueller grid system consists of media, layouts, fractions and templates. The baseline for mueller system is grid. You can define different grids for different media types such as tablet, large screens etc. The media grid can be contained in your layouts. On top of grids and layouts you can define fraction classes.