iota.css is a lightweight CSS layout library which makes it easier to generate flexible, responsive grid layout using CSS grid properties.
dirg.css is an extremely lightweight (~1kb) CSS library which helps you quickly render a responsive grid layout using CSS Grid Layout properties.
BackPack.css is a small CSS grid framework which helps you generate a fully responsive, 12-column based grid layout for modern web design.
Less Grid Boilerplate is a lightweight and standalone CSS/LESS library to generate a basic, responsive, flexible grid layout for modern web design.
Griddd is a lightweight, responsive, CSS flexbox based grid layout that is fully customizable via SASS.