Yeah definitely Blender. It's not that hard to write a media player (hence why there are others like MPC). It's also not that hard to write a Unix kernel (hence why there are others like *BSD). A 3D modeller as complex as Blender though? I can easily imagine a world where it didn't exist and we were all stuck with Povray or whatever.

Kind of like the situation with CAD. (Though the FreeCAD 1.0 release seems to be finally vaguely usable based on my brief play with it so that might have changed.)