Code:
http://www.cocreate.com/products/PE2/ModelingPE2.aspx
PE means personal edition, and after registering (sigh!) you can download and install this free version of CAD software. Before using it, it has to be activated. If you have installed it on a machine with internet connection and MS IE, it probably will activate automatically. If not, you will have to (double sigh!) go back to the website, log in and ask for a code. The whole procedure will demand some patience, so be prepared. Also, when you try to load the tutorial files, you must be online. But you can, inside the tutorial browser, right-click on the file link (e.g. Engine.pk2) and see the properties of that link:
Code:
http://ftp2.cocreate.com/software/Common/OSMPE/training/Engine.pk2
So it really takes some time until you get the ball rolling. Data exchange with other programs is not possible as far as I can see. There is a VRML exporter which does not work, so that's why you get this software for free.
hint: to navigate in the viewport, use the ctrl key, not the usual alt key. 3dx controllers are supported and pre-programmed, which is very nice.