Gecko is the layout engine developed by the Mozilla Project and used in many apps/devices, includingFirefox andFirefox OS.

Webbrowsers need software called a layout engine to interpretHTML,CSS,JavaScript, and embedded content (like images) and draw everything to your screen. Besides this, Gecko makes sure associatedAPIs work well on every operating system Gecko supports, and that appropriate APIs are exposed only to relevant support targets. This means that Gecko includes, among other things, a networking stack, graphics stack, layout engine, a JavaScript virtual machine, and porting layers.

Since all Firefox OS apps are Web apps, Firefox OS uses Gecko as its app runtime as well.

See also

• Gecko on Wikipedia