Resources and materials to get yourself started with open source
WebDriver for Firefox
XSS sanitizer for HTML, MathML and SVG
HTML, CSS and JS framework for developing responsive websites and apps
HTML to PDF converter for PHP
Web Extension for saving a copy of complete web page in a single file
Bootstrap 5 & Material Design 2.0 UI KIT
A static analyzer for Java, C, C++, and Objective-C
Happy DOM is a JavaScript implementation of a web browser
Static site generator that supports Markdown and reST syntax
AdminKit is a free & open-source HTML dashboard & admin template
Converts CSS selectors to XPath expressions
Allows to easily create, process and reuse HTML forms
Tabler is free and open-source HTML Dashboard UI Kit
Lighter, faster browser kernel of blink to integrate HTML UI in apps
An extensible Markdown Editor, Viewer and Weblog Publisher for Windows
Build GUI for your Python program with JavaScript, HTML, and CSS
Open Source UI Kit built on top of Bootstrap 5 and plain JavaScript
A JS-independent, tree-shakeable CSS framework
Status, process, and documents for ECMA-262
PSWriteHTML is PowerShell Module to generate beautiful HTML reports
Ruby HTML and CSS sanitizer
Tool to work with XML and HTML from Ruby
openvpn-monitor is a web based OpenVPN monitor
A collection of all country flags in SVG