This fully featured 3D authoring package contains everything that you need to build 3D models, add textures and lighting effects, render the models and even create cinema quality animations.

It used to cost around 360, but then Microsoft bought the technology for Virtual Earth and now it's available for free.

Caligari pioneered the use of 3D direct manipulation controls and trueSpace7.5 introduces the third generation of context based 3D controls which you can easily edit. The user interface has been enhanced to provide a series of powerful and customizable 2D layouts which support different work styles as well as series of 2D editors such as Link editor, Script Editor, Panel Editor etc.

Visit: trueSpace7, Introduction

Also see list of 48 free Microsoft software at Techradar.