Autodesk's Revit is Building Information Modeling software for Microsoft Windows, currently developed by Autodesk, which allows the user to design with both parametric 3D modeling and 2D drafting elements. Building Information Modeling is a Computer Aided Design (CAD) paradigm that employs intelligent 3D objects to represent real physical building components such as walls and doors. In addition, Revit's database for a project can contain information about a project at various stages in the building's lifecycle, from concept to construction to decommissioning. This is sometimes called 4D CAD where time is the fourth dimension.