eXtensible Hypertext Markup Language

In short

Universal language of the Web; deals with very rich layout; comparable to PDF; works together with CSS to achieve subtle results; looks perfect from the outside, may look horribe from the inside.

item info
types Markup
preferred ⚠️ under conditions
extensions .htm, .html
related formats CSS, HTML, JavaScript, JSX, Markdown, SGML, TeX, XML, XSLT
wikipedia XHTML

See also