This is a tool to assist with the development for Factorio Soft Mods. It works by monitoring a folder recursively for a changes in files (that match a list of extensions), and then insert those changes into the master zip.
I got the save file (and the code within) from a public online game. I'm not sure of the authors except where they documented in the code --- Sorry! I believe the internal name for the map is called labyrinth.