3D Viewers and Tools (for OBJ deliverables)
3DF Zypher Free
Free “lite” version of the 3DF Zephyr. Great for viewing 3D models.
MeshLab (Open Source)
MeshLab is an open source system for processing and editing 3D triangular meshes. It provides a set of tools for editing, cleaning, healing, inspecting, rendering, texturing and converting meshes.