Image Converter Plus - Image Converter Plus is a multifunctional conversion and resizing tool for Windows operating system.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
ImBatch - ImBatch is a batch image processor with a nice graphical user interface.
FreeCAD - An open-source parametric 3D modeler
FileStar - With FileStar you can "do anything with any file".
meshmixer - meshmixer is an experimental 3D modeling tool for making 3D mashups without too much hassle.