gerillass
Gerillass is an open-source toolkit that contains a set of Sass mixins to help designers and developers to create better, faster and consistent user interfaces.
postcss-insert
A postcss plugin that inserts one css classes properties into another, like Sass @extend...only better
sass-mixkit
A lightweight collection of useful Sass mixins and functions.
@sassify/prefixer
Набор миксинов на языке CSS-препроцессора Sass для генерации CSS-свойств с необходимыми браузерными префиксами