Floorplanner - Floor plan interior design software. Design your house, home, room, apartment, kitchen, bathroom, bedroom, office or classroom online for free or sell real estate better with interactive 2D and 3D floorplans.
FreeCAD - An open-source parametric 3D modeler
Sweet Home 3D - Sweet Home 3D is a free interior design application that helps to draw the plan of house, arrange furniture on it and visit the results in 3D.
MacDraft - MacDraft Professional, powerful 2D CAD, drafting, technical illustration, architectural drawing and...
SketchUp - 3D for Everyone
ImplicitCAD - ImplicitCAD is a programmatic CAD program, implemented in Haskell.