- [[wp]] https://en.wikipedia.org/wiki/Polyfill_(programming)
	- In [web development](https://en.wikipedia.org/wiki/Web_development "Web development"), a **polyfill** is code that implements a feature on [web browsers](https://en.wikipedia.org/wiki/Web_browser "Web browser") that do not support the feature. Most often, it refers to a [JavaScript](https://en.wikipedia.org/wiki/JavaScript "JavaScript") [library](https://en.wikipedia.org/wiki/Library_(computing) "Library (computing)") that implements an [HTML5](https://en.wikipedia.org/wiki/HTML5 "HTML5") or [CSS](https://en.wikipedia.org/wiki/CSS "CSS") [web standard](https://en.wikipedia.org/wiki/Web_standard "Web standard"), either an established standard (supported by some browsers) on older browsers, or a proposed standard (not supported by any browsers) on existing browsers. Formally, "a polyfill is a [shim](https://en.wikipedia.org/wiki/Shim_(computing) "Shim (computing)") for a browser [API](https://en.wikipedia.org/wiki/Application_programming_interface "Application programming interface")".[\[1\]](https://en.wikipedia.org/wiki/Polyfill_(programming)#cite_note-speakingjs-1)
	
	https://twitter.com/flancian/status/1391447591330750464