Open Source : Sweet Home 3D

I just read about through a Sourceforge mailing. Apparently, it is a cross-platform (Windows, OSX and Linux) and Open Source home modeling application, with the possibility of running online. The export to 2D drawings uses Scalable Vector Graphics (SVG), which is slightly similar to PDF, but in an open XML-based format and the 3D model can be exported into an OBJ file (the old ASCII-format from Alias Wavefront software, before it became Maya).