I have been building game worlds since some time in the 1980s, some organizations have appeared again and again.

FFTC - The Far Flung Trading Company specializes in those frontier areas of the world that other merchant houses aren't interested in.

The Kassen Kompany - Formed by a Gagak DeKassen (A PC I played in another DMs game) and his party. They held land, ran businesses and had a small merchant house. The Merchant House got hived off into the FFTC, while the rest of the holdings got 'distributed' when the game finished. Obe finished up in Gagak's possession, and still contribute his family finances.

Church of Way - Originally The Brothers of the Way, now the Church of Way, this small church builds bothies and hostels for travellers. The original Way House was built by Yuthric Green-Teeth, and then grew into a widespread religious organization.

The Raven College of Armes - Every game-world needs its honours and titles - The Raven College of Armes has done that since the very first world that I built. It was started by a PC (turned NPC) druid, as an analogue for the early Celtic Druidic/Bardic colleges in a traditional fantasy world.

The Golden Billet - A new organization that has only appeared in a couple of games, so far. It provides 'contracted out' protective services to states and organisations. A pure NPC organisation.