Games that have been programmed from scratch without the use of any pre-existing game-making software.
Game engine developed by a independent game creator specifically for their game(s)
The Irrlicht Engine is an open source high performance realtime 3D engine written in C++. It is completely cross-platform, using D3D, OpenGL and its own software renderers, and has all of the state-of-the-art features which can be found in commercial 3d e
txtr is a small web based Python application come engine that allows you to turn interactive fiction into real time texting based text adventure games.