Forge World
Forge World is a term associated with Warhammer 40000. It has two definitions.
The first, fluffy, definition is an entire world converted into a factory; one that runs at high capacity, even for its size. They produce everything from laspistols to Land Raiders to Titans, so they are needed to keep the Imperial war machine trundling forward. Because of their nature, the Adeptus Mechanicus highly regard these worlds as holy places, and the Mechanicus owns just about all of them, which is fine since there are only a few of them and the Mechanicus is best at maintaining that shit. Losing a single one is considered an unacceptable loss by the Mechanicus, and the Imperium as well since it'll be harder than fuck to fill in those planet-sized gaps in their industrial sector. In the fluff, there is actually a forgeworld called 'Zpandex'.
The other meaning of Forge World is if you took Games Workshop and leveled it up a few times. It's a subsidiary of GW and produces high-end resin-cast models for 40k, Battlefleet Gothic, and Epic. Over time it's since gone about producing its own range of models and own rule sets for a huge array of different factions, and even has its own home-grown Imperial Guard variants (the badass Death Korps of Krieg and Elysian Drop Troops). The awesome-looking Chaos Renegades for Lost and the Damned also came from here.
It should be noted however, they are still a leveled-up version of Games Workshop. While GW is already an expensive company, "high-end" means oodles of awesome details in just about every model FW makes (unless you can't take mold lines and massive membranes of kit off your models). The problem, however, is that they charge an arm, leg, and at least one of your testicles for most models*. (The testicle part is probably to let you know that these models aren't for girls, either.)
"How expensive?" you may ask. Ok, go look at their prices. See those little squiggly lines next to the numbers? Those are pounds, which are worth more than dollars. Now apply the conversion rate and weep. Disregard this however if you live in Australia, as Forge World models, thanks to the conversion rate, are actually cheaper then their plastic counterparts. Fucking Games-Workshop.
In conclusion: "Five hundred quid for a fucking titan? If I ever find the fucker responsible I'm going to beat them to death with their own HHHHHHHHHHHhhhhhhhnnnnnnngggggg-".
*This doesn't mean to imply that you're limited to only two models unless you happen to be a serial killer or a corrupt mortician.