TL;DR - Maratis3D
Torque3D was once a great tool, superior to Unity by then, but someone "really smart" decided to drop OpenGL in favor of Direct3D, what a good decision it was...
This means the engine couldn't target linux and macs and, on top of that, possible ports to consoles like playstation or mobile platforms were undermined.
In other words, they killed themselves.
To try and survive from its previous user base, it has gone Open-Source under the MIT. I guess this was an attempt to keep their asset store alive for a little longer.
Who knows if the community wouldn't be willing to undo their stupidity and rebuild OpenGL?
Well, it has been years now, and I have seen nothing but but rudimentary OpenGL ports.
So, if you are considering using Torque3D, consider the following:
- Your game will be windows exclusive or web-based, unless you help develop and use a torque3d port.
- all ports are still in-the-works, and the linux branch on GitHub is tens of thousands of diffs behind.
- Small community when compared with Unity ($$$) and other alternatives.
- It is slowly decaying, I see less and less content about it everywhere.
- Opensource, differently from Unity (that has a really high cost for an individual).
- Great license; the X11 license is simply great for users.
- Good and cheap game editor (Its called Torsion iirc)
I really hope Torque3D can fix its mistakes and use OpenGL for all platforms that needs it! This would mean a great engine getting back in the race.
As an alternative, it is really easy to point you to a great 3D game engine, that I personally consider to be almost as good as Unity:
Maratis3D, here: http://www.maratis3d.org/