Defold is a completely free to use 2D and 3D game engine for development of console, desktop, mobile and web games. There are no up-front costs, no licensing fees and no royalties. The source code is made available on GitHub with a developer-friendly license. The Defold editor runs on Windows, Linux and macOS and includes a code editor, debugger, profiler and advanced scene and UI editors. Game logic is written in Lua with the option to use native code to extend the engine with additional functionality.
Depending on target platform the engine uses either OpenGl, Vulkan, WebGL, Metal (through MoltenVK) or console proprietary rendering.
3D models use the glTF format.