The article attributes all these free engines to Unity but I think they've missed 20+ years of videogame history. First, Valve has always been very open to game mods. Some of their most popular franchises (TF & CS) grew out of the mod community around HL1 and they've always made tooling available for the Source engine. HL1 was based on the Quake engine and id has always embraced the mod community. Id software has als…
> Ogre 3D I recently chose to give up on Ogre3D as I was completely frustrated by my inability to make it run on mac. It's also way too big (I don't know if OOP is a reason for that, but I still tend to dislike OOP nevertheless). For example it doesn't seem that you can choose to not use the scene graph. I loved that engine at some point, but as time passed, I wasted an incredible amount of time trying to either buil…
You can try http://libcinder.org , http://www.openframeworks.cc or http://www.sfml-dev.org