Tombstone Engine Review

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.