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 asset creation.
F3D is a fast and minimalist 3D viewer desktop application. It supports many file formats, from digital content to scientific datasets (including glTF, USD, STL, STEP, PLY, OBJ, FBX, Alembic).