Campaign Cartographer - Campaign Cartographer is the leading map making software for games (RPGs, miniatures and wargaming).
Godot Engine - Feature-packed 2D and 3D open source game engine.
DUNGEONFOG - Online authoring tool to draw rpg maps & dungeons, create dynamic notes and share your maps online. Create dungeons, world maps and more with the easy to use map editor and create your game master notes dynamically.
GDevelop - GDevelop is an open-source game making software designed to be used by everyone.
Inkarnate - A free-form map editor for role-playing games, focusing on overland and continental maps.
Unity - The multiplatform game creation tools for everyone.