godot

Godot Engine is a free and open-source game engine, which is the software developers use to build video games. It supports both 2D games (flat, like classic platformers) and 3D games (with perspective and depth, like first-person shooters), and it lets you do both inside one unified editor instead of switching tools.

The way it works is that the engine ships with a comprehensive set of common tools — for things like scenes, scripting, physics, sound, animations, and visual editing — so that game makers can focus on the actual game rather than rebuilding those foundations from scratch. Once a game is finished, the engine can export it with one click to many platforms: the major desktop systems (Linux, macOS, Windows), mobile (Android, iOS), web-based platforms, and consoles. The engine itself is written in C++.

You would use Godot if you want to make any kind of 2D or 3D game and prefer a single tool that handles the whole pipeline, especially if you want to keep ownership of your games without paying royalties. The license is permissive MIT, which according to the README means no strings attached and the user's games are theirs down to the last line of engine code. Development is community-driven and supported by the not-for-profit Godot Foundation. Godot was originally an in-house engine developed by Juan Linietsky and Ariel Manzur for work-for-hire titles before being open-sourced in February 2014. Official binaries, documentation, demo projects, and a list of awesome community resources are linked from the README.