Simple. Robust. Responsive. Flexible.
Based on Flexbox (CSS Flexible Box Layout Module), Gridlex is a very simple css grid system to quickly create modern layouts and submodules.

Gridset is described as 'Tool that allows you to create sets of responsive grids for your site' and is an app in the development category. There are 2 alternatives to Gridset for a variety of platforms, including Web-based, BSD, Self-Hosted, Mac and Windows apps. The best Gridset alternative is Gridlex, which is both free and Open Source.
Simple. Robust. Responsive. Flexible.
Based on Flexbox (CSS Flexible Box Layout Module), Gridlex is a very simple css grid system to quickly create modern layouts and submodules.

The 960 Grid System is an effort to streamline web development workflow by providing commonly used dimensions, based on a width of 960 pixels. There are two variants: 12 and 16 columns, which can be used separately or in tandem.