Harfang 3DWebsite :
https://www.harfang3d.com/Hybrid License : GPL/LGPL or Proprietary (free as long as you don't reach a revenue threshold, otherwise it's royalty-based).
Platforms : Win, Linux,
OS XComplete framework that does 3D (OpenGL/DX/Vulkan), 2D and VR (OpenVR), physics (Bullet Physics), audio, video, pathfinding (Recast) and embeds Lua.
It is available in several flavors :
Engine demoreel :Since the of 2021, HARFANG is
open-sourceIn addition to the runtime, we now provide
HARFANG Studio, a language-agnostic 3D editor. Any 3D content you create in HARFANG Studio can be loaded/run either in Python, Lua, Go or C++.
Tutorials can be found on youtube, we're creating them as fast as possible
I just updated this, since a lot of changes occured since the initial post
.