World Wide Web Consortium (W3C)
W3Schools Online Web Tutorials
Bootstrap is a free and open-source CSS framework directed at responsive, mobile-first front-end web development.
Environment for testing code
Internet Archive building a digital library of Internet sites
Testing Resources for CMS sites
mysql
phpmyadmin
Freebsd
Apache
Local computer testing environment
WordPress Resources
WordPress CMS Content Management System Platform
Astra WordPress Themes
Themeforest Thousands of WordPress themes
Elementor Web Site Builder
Woocommerce short codes
structured-data
Structured Data and Rich Results
Google Structured Data Testing
Schema
Rich Results Test
Schema Mark up generator
Associations
International Webmasters Association (IWA)