The following renders were created with a 3D content creation software by the name of Blender, which I am a huge fan of, not only for being very very powerful, but also free!
This software is cross platform, portable since you can download it anywhere, and by being open source we have the ability to use it at no cost.
Here is a video I helped create using Blender: video link.
Money for the software comes by donations and sales of tutorial DVDs and Books, there are also free educational tutorials on their website and all over you tube.
Blender’s website address is www.Blender.org