Unity - The multiplatform game creation tools for everyone.
wikidPad - wikidPad is an application for storing thoughts, ideas, todo lists, contacts, or anything else that user can think of to write down.
Godot Engine - Feature-packed 2D and 3D open source game engine.
Wiki on a Stick - Self-contained desktop wiki
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
MyInfo - MyInfo is the most versatile organizer for Windows