This still suffers from the rounding error seen here [http://i.imgur.com/DXjVN.png].

Otherwise, yup... it's a grid. Looks like they're setting the grid elements to display:inline... which seems weird and unnecessary to me? Block elements don't belong inside inline elements.

I hate to keep posting this, but I've been unable to find fault with this grid [https://github.com/stubbornella/oocss/blob/master/core/grid/...] code. .lastUnit spans the pixel gap on the rightmost, nestable, extendable, fluid widths.

The two are mostly the same idea, but I think the OOCSS project implements it better and works with more browsers.