Unity - The multiplatform game creation tools for everyone.
FontForge - Free (libre) font editor for Windows, Mac OS X and GNU+Linux
Godot Engine - Feature-packed 2D and 3D open source game engine.
Glyphs - Make everything from dingbat webfonts to full-fledged text typefaces in the most Mac-like font...
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
BirdFont - Birdfont is a free font editor which lets you create vector graphics and export TTF, OTF, EOT and...