Routes players between the servers of a split Factorio world. This server handles one planet (or the space platforms); the manager tells it what the others are.
Lua libraries for use by other mods and submods that are parts of a larger mod.
Providing the player with new tools or adjusting the game interface, without fundamentally changing gameplay.
Generic localhost UDP transport for Factorio mods: framed events, chunking, request/reply and acknowledgements.