All of the above website templates are all written with HTML5 and CSS3. HTML5 is the newest version of HTML which is the coding language used for websites. It stands for Hyper Text Markup Language. It's aim is to improve the language with support for the latest multimedia while keeping it easily readable by people and understood by computers and devices.
CSS3 is the newest version of CSS which is a language used for describing the look and formatting of a document written in HTML. It stands for Cascading Style Sheets. It is designed primarily to enable the separation of content from presentation.