Most widely used game engine

In its busiest month so far – March 2014 – a total of 626,118 people used the Unity game engine to develop videogames and other 3D media. Whether for personal projects or major commercial games, a great many indie developers use the Unity engine, including FRACT OSC (Phosfiend Systems, 2014), Kentucky Route Zero (Cardboard Computer, 2013), Gone Home (2013) and Thomas Was Alone (Mike Bithell, 2012). Though best known for high-fidelity 3D graphics, it's also more than capable of creating 2D games as well. Free to use and inexpensive to release commercial games with, Unity comes with a community of fellow developers and libraries of graphical and scripting assets.