Freeplane began as a fork of the Freemind project. While maintaining comparability with Freemind file format, it has far outpaced in features and development. As of 3/5/2022, the latest Freeplane update (1.9.3) is 3/5/2022 vs Freemind was last updated (1.0.1) 2/5/2016. Active, helpful community.
Unity - The multiplatform game creation tools for everyone.
Xmind - Xmind is a brainstorming and mind mapping application.
Godot Engine - Feature-packed 2D and 3D open source game engine.
FreeMind - FreeMind is a premier free mind-mapping software written in Java.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
vym - VYM (View Your Mind) is a tool to generate and manipulate maps which show your thoughts.