Factorio's Official Mod Portal: The Game That Built Modding Into the Main Menu
Factorio has an in-game mod browser and a first-class Lua API, because Wube built modding in from day one. It is the cleanest official mod pipeline in the industry.
Most games treat modding as a bolt-on that arrives years later. Factorio built it into the main menu from the start. Open the game, click Mods, and you are browsing and installing from an official portal with one click — no external manager, no file juggling.
Underneath is a first-class Lua modding API with extensive documentation and a dedicated wiki. Mods can add items, entities, and entire systems, and because the API is the same one the game itself is written on, a Factorio mod can be as deep as the base game. The result is a portal holding well over a hundred thousand mods, from tiny quality-of-life tweaks to total conversions.
Wube's approach is the template every other studio should copy: modding as a first-class feature, documented and versioned alongside the game itself. It is why Factorio mods rarely break on update, and why the game's mod scene is the healthiest in its genre.