Pmx Editor - PMX Editor is for editing 3D model data to be used in MikuMiku Dance.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
DeleD CE - DeleD is a 3D modeler and level-editor combined into one.
Sketchfab - Sketchfab is an industrial design software tool is useful for ideation and for beginners in the industrial design field.
3DTin - 3DTin is a browser based 3D modelling tool.
Anim8or - Anim8or is a 3D modeling and animation program that is aimed at beginners with its intuitive and easy-to-use set of tools.