Apache is a free and open-source cross-platform web server software.
Websites that have a shopping cart or checkout page, either using a known ecommerce platform or a custom solution.
Google Tag Manager is a tag management system (TMS) that allows you to quickly and easily update measurement codes and related code fragments collectively known as tags on your website or mobile app.
Sass is an extension of CSS that enables you to use things like variables, nested rules, inline imports and more.
TYPO3 is a free and open-source Web content management system written in PHP.