Cheetah3D is described as 'computer graphics program for 3D modelling, animation and rendering. It is written in Cocoa for MacOS' and is an app in the Development category. There are more than 50 alternatives to Cheetah3D for a variety of platforms, including Windows, Mac, Linux, iPad and Android. The best alternative is Blender, which is both free and Open Source. Other great apps like Cheetah3D are MakeHuman (Free, Open Source), Autodesk Maya (Paid), Wings 3D (Free, Open Source) and ZBrush (Paid).
MakeHuman is an interactive modelling tool for creating realistic 3D human characters. These models can be exported to several computer graphics and animation platforms including Blender, Unity 3D, Unreal Engine, OpenSim and Second Life.
Wings 3D is a subdivision modeler inspired by Nendo and Mirai from Izware. It is possible to assign materials, vertex color, UV coordinates and textures, but there will be improvements in those features before Wings goes 1.0.
Sketchfab is the first web service to publish interactive 3D content online in real-time without plugins. Every new format has its global platform: videos have Youtube, photos have flickr, sounds have Soundcloud... Now 3D files have Sketchfab.
Rhino can create, edit, analyze, document, render, animate, and translate NURBS* curves, surfaces, and solids, point clouds, and polygon meshes. There are no limits on complexity, degree, or size beyond those of your hardware.