Other free software's that can import Sculptris models

[Justanother1]

At the top of the list is http://www.wings3d.com/ This forever has been one if the best and most supported freeware modelers. Although the opengl renderer does not support your Sculptris model's normal map, the tools, features and import/export options makes Wings3D a must have for any serious modelers toolbox. As well as importing your model, Wings3d is also a great box modeler, very usefull for making mechanical, symmetrical models like cars, guns, skyboxes and more.This is also a great tool for building basemeshes to use in Sculptris. Imagine having horns, wings, lower-poly eyes, teeth, buttons and more, ready to import into Sculptris. Just build your model in Wings3D, then select all in polygon mode, right click and choose Tesselate-triagulate, then export. Your model will import into Sculptris with no problem.

The Flagship of the Freeware line has got to be Blender 2.57 http://www.blender.org/education-help/. It's completely redesigned interface and community support has brought it from "way too confusing" to "why aren't they charging money?"! Extremely easy to rig and animate characters, GLSL shaders in the viewport, fluid and cloth simulation, test game physics on the fly, retopology using snap tool, vertex and texture painting and sculpting tools as well. If your playing with Sculptris, download Blender 2.57 and watch some tutorials on vimeo and youtube. Trust me you gotta get this !! Watch this short movie made entirely in Blender 2.5x

[Justanother1]

If your thinking of gaming, try http://www.3drad.com/ Easy to use free game making software is based on Directx. Entire games can be made without any coding. And for more complicated games there's plenty of help in the forums. Your Sculptris models can be directly exported from Wings3d for import into 3DRad, or they can be bone animated in other freeware and then exported as Directx (.x) files. Of course your Sculptris normal maps are supported by Directx and thus 3DRad.
CharacterFX is an oldschool but powerfull bone animation tool from http://www.insanesoftware.de/. It is one of the easiest tools for setting up skeletons and animating 3D models. Its only drawback is that it was built on the older Directx8 and so importing and exporting sometimes needs a work around which is easily done usingFragmotion from http://www.fragmosoft.com/. This software is still under development, and while not Free, is fairly cheap compared to most 3D software. A trial version can be downloaded and used past the trial time, as long as you can put up with the pop-up mascot. My workflow for these two programs is .....
Import .obj into and then back out of Fragmotion. Import that .obj into CharacterFX. Build rig and animate in CharacterFX, exporting single animations. Import and stack those single animations in Fragmotion to a fully animated character. It seems like a lot to go through, but CharacterFX is still easier to Build and Animate in.
Also you might try http://www.dxstudio.com/download.aspx. The Freeware Edition can be downloaded from Microsoft. The user interface is fairly user friendly, as well as many tutorials and example content that can be downloaded as well. And its Microsoft, the makers of DirectX, so you get all the goodies to play with as well as a wealth of information.