The Semantic Grid System (Less.js-Powered)
The Semantic Grid System is a fresh approach to CSS grids which allows us to define column-gutter widths, choose the number of columns and switch between pixels and percentages. And all these without the -kinda ugly-
.grid_x classes used in the markup
The grid system is responsive as well and manipulating it using media queries is very easy.
There is also a detailed introduction of Semantic.gs in Smashing Magazine that is written by the developer himself.