Right, I see...

In fact it renders computer-simulations of architectural drawings.
Must say I visited an exhibition on this kind of works dating from the time the architects still made them with pencil, pen and watercolours...there were unbelievable beauties there...
I noticed that the same resellers also sell VectorWorks. Some say that this prog is much better than Autocad. Not that I know of as I don't see any personal use for either...