Blender is a free 3D application. It is licensed under GNU general public license. If you are into 3D modeling than this is great software for you. The application is very comparable to other 3D modeling software and even proprietary ones. If you want to learn more about 3D computer graphics then check out Blender at their website. There is also a large online community for Blender so if you are new you can learn a lot from forums and community members. If you are wondering, Blender works on most platforms and especially Linux!