The HyperText Markup Language, or more commonly known as HTML, was created by Tim Berners-Lee and the W3C in 1993. It is compatible with Cascading StyleSheets, or CSS. HTML's latest version is HTML5.2, pushed in 2017. It is used for building websites using a series of tags like <p></p> or <a href="if.php"></a>.
The HyperText Markup Language (HTML) is a popular web design language for a very long time.
An alternate term for Mother Tongue, but without the maternal associations. Your cradle language is your first language, the one you learn as an infant. You might learn it from your parents or from a nanny or from wolves.