whatwg

wpt

+10

Test suites for Web platform specs — including WHATWG, W3C, and others

whatwg/html

+8

HTML Standard

happy-dom

+8

A JavaScript implementation of a web browser without its graphical user interface

graphql-yoga

+3

🧘 Rewrite of a fully-featured GraphQL Server with focus on easy setup, performance & great developer experience. The core of Yoga implements WHATWG Fetch API and can run/deploy on any JS environment.

validator

+3

The Nu Html Checker (vnu)

parse5

+2

HTML parsing/serialization toolset for Node.js. WHATWG HTML Living Standard (aka HTML5)-compliant.