The Grand Guilds

Since ancient times, craftsmen and tradesmen tended to form associations based on their trades in the form of guilds. The guilds controlled secrets of traditionally imparted technology, the “arts” or “mysteries” of their crafts.
The advancements in magical science during the Age of the Varn led to associations specializing in the creation of mechana (magic items). This came to a head with the invention of Magifactories, which allowed the mass production of mechana. All this led to the formation of much larger and powerful guilds, ones that eventually came to span the entire world. These were the Grand Guilds and they were in many ways similar to multinational corporations.
Over time, the Grand Guilds became almost as powerful as nations, and fielded small armies of their own, which were often used as mercenaries by other states and official entities.
The majority of all mechana created during the Age of the Varn (and virtually all of the most powerful ones) were products of the Grand Guilds.
The War of the Varn destroyed all of them, but their legacy (and mechana) have survived to this day in the hands of heroes, villains, lost in lightless dungeons, or kept in hoards of dragons.
Some of the most noteworthy of these guilds (at least to adventurers looking for magic items that are useful to them) are: Blackblade Armaments, Varnian Mechanics, Hoplon Industries, Sentinel Serpents, Yggdrasil Creations, Crescent Moon Works, Blüt Engel.