This chapter explains one of the most important components of the web: the development and standardization of Hypertext Markup Language (HTML) and DOM (Document Object Model) which are used for creating web pages and applications. In 1994, Tim Berners-Lee established the World Wide Web consortium (W3C) to work on HTML development. In 1995, the W3C decided to introduce a new standard, WHTML 2.0. However, it was incompatible with the older HTML/WHTML versions. This led to the establishment of Web Hypertext Application Technology Working Group (WHATWG) which worked externally to the W3C. WHATWG developed HTML5 which was adopted by the major browser developers Google, Opera, Mozilla, IBM, Microsoft, and Apple. For this reason, the W3C decided to work on HTML5, leading to a joint WHATWG/W3C working group. This chapter explains the development of HTML and WHATWG’s Living Standard with explanation of ongoing splits and agreements between the two fora. It explains how this division of labour led to W3C focus on the main areas of web architecture, the semantic web, the web of devices, payments applications, and web and television (TV) standards. This has led to the spillover of work to the W3C from the national sphere, notably in the development of copyright protection for TV streaming.