A common API developed to enable rich media advertising in mobile in-app environments. MRAID is a standardized set of commands, designed to work with HTML5 and JavaScript, that developers creating rich media ads use to communicate what those ads do with the apps they are being served into – expand, resize, get access to device functionalities such as calendar events, etc. MRAID is only relevant for mobile rich media creatives that run in an in-app environment, not mobile web.