moving them onto the Stage using the insert command, like insert CoolOval into the stage, which would make both the oval and rectangle appear. GUIs were constructed solely from Actors. A window-like object could be built out of an opaque rectangle containing other objects (e.g., close buttons, widgets). Every Actor's drawing style was controlled by a Renderer, which aided the GUI building process. For instance, the BevelRenderer could be used to bevel the edges around an Actor, producing an effect like Windows 3.x controls or the title bar in NeXTSTEP. Other renderers included color and image fills, gradients, tiles and blends. Although there was no difference in programming terms, basic objects like rectangles were classified as "geometry actors" while more traditional GUI elements like buttons were known as "interface actors". The Stage captured user-generated events like mouse-down clicks and key presses and sent them to the Actors. The visual hierarchy determined which object would receive the message first - the Stage was Z-ordered and objects closer to the front got the messages first. Messages could be passed up the class/prototype hierarchy with the do inherited command. Project Builder Project Builder was an environment for building visual development environments. It provided code editing, debugging, graphics and smart component library, runtime targeting support and a direct manipulation graphical interface builder system. A key element of the Builder system was the "Overviewer" panel, which held a categorized list of all of the objects in the currently opened project. These include libraries, user-created functions and methods, variables, and so forth. These could be examined and edited by double-clicking on them, or by clicking in an associated pop-up menu that appeared on the object when it was selected in the GUI builder. The Object Editor that appeared listed the object's "properties" (instance and class variables) in one pane, and it's "handlers" (methods) in another. The GUI builder included a drag-and-drop based system for constructing visual objects. SK8 did not have traditional "screens"; it used an invisible "Stage" object that served as the background for managing events and visual objects. One interesting aspect was that no windows, in the traditional sense, were needed or expected to display anything. In fact, any visual object could have window-like behavior (through its drag-and-drop and other smart properties). SK8 did, however, include a system for editing and programming complete menu bars, a feature that HyperCard lacked. Another oft-requested feature from