Amethyst vs Tombstone Engine

Amethyst is published under the MIT license making it open-source and id offered completely free. This allows anyone to give the tiling window manger a try, which is great.

The application was written in Objective-C, but was recently updated and completely rewritten in Apple's new native language Swift.

As it's designed to work closely to how xmonad, Amethyst uses keyboard shortcuts to control the windows being used, meaning no mouse input is necessary. This can make for a faster way to control windows.

No CONFIG file provides security and will avoid making amethyst crash. Instead configured via simple UI

Tombstone gives full access to the clean and professional C++ source code allowing editing and upgrading anything in the system.

Including extensive documentation both in code as well as online along with a wiki, tutorials and a demo game.

Due to the well-organized, highly modular design of the engine adding custom functionality is easy.

Comes integrated with support for physics, audio, networking, input devices, resource management as well as modern features such as real-time shadows, horizontal mapping, voxel-based terrain, dynamic lighting, post-processing effects and much, much more.

Tombstone has a small, tight-knit community that's well educated and professional. Eric Lengyel, the main developer, can often be found giving thorough advice to users on the forums.