is a popular, albeit aging, software tool specifically designed for creating custom world maps for Hearts of Iron IV (HOI4) mods. Developed by community member Jamestom999, it automates the tedious process of generating the numerous game files (provinces, terrain, heightmaps, and rivers) required for a functional custom map. Key Features and Functionality
Or download the prebuilt binaries for Windows/Linux/macOS from the releases page . mapgen v2.2
That magic was MapGen v2.2.