browserling - Live interactive cross-browser testing from your browser.
One Month HTML - Learn HTML in 30 days
Browsershots - Browsershots makes screenshots of your web design in different browsers.
Grav - The modern open source flat-file CMS
BrowserStack - BrowserStack is a software testing platform for developers to comprehensively test websites and mobile applications for quality.
Elementor - Elementor is a front-end drag & drop page builder for WordPress.