Blender

Blender is the free and open source 3D creation suite. It supports the entirety of the 3D pipeline—modeling, rigging, animation, simulation, rendering, compositing and motion tracking, even video editing and game creation.

Download link

Blender is also compatible with modding 3D assets for Empire at War Forces of Corruption thanks to Gauklers Alamo Tools for Blender.

ALO importer and exporter

Training/tutorial for non-manifold in Blender