Iteration X - Iteration X allows teams to annotate and edit any live website or web app directly in Chrome.
Unity - The multiplatform game creation tools for everyone.
Edit Any Webpage - Edit any site on the fly - bookmarklet
Godot Engine - Feature-packed 2D and 3D open source game engine.
EditMode - Update website texts in real-time and get a sharable link.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.