In 1985, MiniCad was one of the first computer modeling programs developed for the Mac, and the popular upgrade, MiniCad+, was the first Mac program to offer an interactive 2-D/3-D CAD environment. MiniCad+ introduced the ability to link "intelligent" symbols, like doors, windows, and plumbing fixtures, to a "Worksheet" database, which can be used to build an itemized material list and cost breakdown. Suppose, for example, you have a $2,500 door budget for a house you're designing. Using MiniCad+, every time you draw a door you can check a user-defined "Door Schedule" Worksheet to find out instantly where you stand with costs (see Figure 1). Better yet, if you revise the door specification to replace hollow core birch doors with six-panel oak doors,
