building models

Everyone unfortunately knows DWG (or OpenDWG), DXF and DWF formats from AutoDesk but there are numerous niche model formats developed for specific AEC contexts and the Web. Whilst not household names, formats like CIS/2, IFC, VRML and X3D are interesting formats in their own right. The chances of any of these formats gaining industry acceptance is pretty low but this page from the National Institute of Standards and Technology provides a good rundown on each standard with referring links.

AutoDesk have released a freely downloadable dwg viewer. Whilst it clocks in at a whopping 100meg and is Windows only it does finally provide a free way of natively reading dwg files using only AutoDesk software. Things could be a lot better but at least AutoDesk has a free product on the market for doing this (now they just need to do something that runs on OSX and Linux).