Unity - The multiplatform game creation tools for everyone.
SVG Animation Assistant - Quickly and easily animate Inkscape SVGs.
Godot Engine - Feature-packed 2D and 3D open source game engine.
Vectr - Free vector graphics editor. A simple yet powerful web and desktop cross-platform tool for everyone.
Unreal Engine - Unreal Engine 4 is a suite of integrated tools for game developers to design and build games, simulations, and visualizations.
Hype - Using Hype, you can create beautiful HTML5 web content.