Google Optimize is a free website optimization tool that helps online marketers increase visitor conversion rates and overall visitor satisfaction by continually A/B testing different combinations of website content.
Hypertext Markup Language (HTML) is the standard markup language for documents designed to be displayed in a web browser. It can be assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaScript.
Less which stands for Leaner Style Sheets is a backwards-compatible language extension for CSS. This is the official documentation for Less, the language and Less.js, the JavaScript tool that converts your Less styles to CSS styles.
PHP: Hypertext Preprocessor is a server-side scripting language designed for Web development, but also used as a general-purpose programming language. PHP code may be embedded into HTML code, or it can be used in combination with various web template systems, web content management systems, and web frameworks.
Typekit is an online service which offers a subscription library of high-quality fonts. The fonts may be used directly on websites or synced via Adobe Creative Cloud to applications on the subscriber's computers.