The Columnal CSS grid system is a remix of a couple other grid systems with some custom code thrown in. Columnal is an elastic grid, while some code inspiration (and the idea for sub-columns) are taken from 960.gs. Among its features you can find:

– Built-in debugging CSS to show the structure of any pages being built

– Sub-columns (columns within columns) for more layout options

– Prefix and suffix for extra space within a column before or after content

– Vertical spacing CSS classes

– PDF of grid system for sketching out site before building

– Wireframing templates