htmlvalidator
There are 3 repositories under htmlvalidator topic.
Gemorroj/HTMLValidator
port PEAR package Services_W3C_HTMLValidator
AlbertWiersch/html-validator
CSS HTML Validator is a fast HTML and CSS validator / syntax checker / linter that can also check accessibility, SEO, and more. This project is another way to report issues and feature requests.
Meetpatel-1729/HTMLTagValidater
It validates the HTML tag