EQCSS is a CSS Reprocessor that introduces Element Queries, Scoped CSS, a Parent selector, and responsive JavaScript to all browsers IE8 and up

CSSplus is a collection of CSS Reprocessor plugins that dynamically update CSS variables

Easy to use event-driven CSS variables

Cascading JS Variables with a similar syntax and usage to CSS Variables, implemented in JavaScript

respec allows CSS authors to assign the specificity of a rule separately from the specificity of the selector

A command-line tool to read EQCSS syntax and output parsed queries as JavaScript objects

Build with Container Queries. Ship CSS.