SK8's universe was made up of a multimedia-oriented system using Actors on a Stage. Actors were any objects that were based on the prototype Actor object, which contained the basic framework needed to provide 2D graphics support - the location and size of the object for instance. Actors became visible when they were placed upon the Stage, an invisible background object that captured user events to provide interactivity. In SK8, a traditional window was an object like any other graphics object. When an Actor was on the Stage, it could behave as a window-like object. It was easy to design complex objects that behaved like windows (e.g., a donut-shaped window; its hole's opacity 0%, with content being a text object scrolling around or perhaps a movie playing within its frame). An object known as the "halo" provided resize handles and other widgets for manipulation in a visual development environment.