Buried fiber networks, 32-tile powered relays, Data Centers, Infrastructure Science, and electrified factory flooring. Autonomous personal vehicles for multiplayer road networks.
Mods introducing new content into the game.
Transportation of the player, be it vehicles or teleporters.
Augmented or new ways of transporting materials - belts, inserters, pipes!
Furnaces, assembling machines, production chains.
Changes to power production and distribution.