* Yes, Weyland-Yutani is in Firefly. In the two-hour pilot episode, the W-Y logo appears on the head-up display of the AA gun fired by Mal Reynolds, during the Battle of Serenity Valley. It's there, for real. http://firefly.wikia.com/wiki/Weyland-Yutani Look at the image close-up... that is their corporate logo, top and center. Wow. They show up in "Angel" as well. Joss Whedon loves Weyland-Yutani.
Aqua Regio: This firm got its start on Ariel, but moved en masse to a skyplex in the Boros system, where it is now plays a significant role in the development of the latest Alliance Navy systems. Aqua Regio focuses on cryogenics, space exploitation, life support systems, and astrogation technology. They also make a good income from hauling water ice to outlying colony world. Recently they expanded into banking and mass media, despite stout competition from more established firms like Orbus.
Ariadne-Jiyin: A mysterious and powerful entity, Ariadne-Jiyin has purchased large tracts of land on the small moon Corrine, where it maintains its primary research facilities. The primary public headquarters are located on Ariel. This megacorporation deals almost entirely in biotechnology; pharmaceuticals, genetic engineering, and ultratech chemical production. Little is known about Ariadne, as it maintains a relatively low profile for a Megacorporation. They are most famous for custom geneering, but are also well known for the low cost, quality medical products that they frequently make available to new settlements at cost.
Durham-Blackwood: Founded by a consortium of business-minded nobles on Persephone, Durham-Blackwood is one of the smallest Megacorporations. They focus on computers, commercial software, electronics, and some limited genetic engineering, but are most famous for their cutting edge Cortex products. Headquartered on a private island on Persephone, Durham-Blackwood has a somewhat tarnished reputation due to their involvement in past bribery scandals, which allowed them to become a part of the Cortex backbone.
Kapoor Group Unlimited: Founded by tycoon and philanthropist K.R. Kapoor, the Kapoor Group Unlimited is run by the precepts outlined in the "White Book", a lengthy work of morals and philosophy based on the Bahai faith. The corporate headquarters on Sihnon also serves as the central temple for the sect. The business is centered on resource exploitation, banking, and mass-media, with sidelines in agriculture, vehicle production, consumer goods, and highly advanced robotics. Kapoor Group Unlimited devotes itself to a policy of interplanetary harmony and a generally progressive agenda. Among all of the Megacorporations, it is probably the most popular, due to intense and aggressive efforts by their public relations department.
Liang Cyberdyne: A top line electronics firm based in Londinium, Liang Cyberdyne is best known for its high quality premium electronics and weaponry. Most of its products are expensive status items, including the megacomputers much in demand around the core. Liang Cyberdyne is a bitter rival of Durham-Blackwood for Cortex contracts, as it was founded as an offshoot of Durham-Blackwood by disaffected executives.
Magnus Manufacturing: One of the most powerful of the Megacorporations, Magnus is unusual for being headquartered on Beaumonde, where it runs countless factories and other facilities. Magnus is involved in nearly every form of heavy industry; mining, power generation, weaponry, vehicle construction, consumer goods, mass media, and finance. The leadership of Magnus controls an invisible empire of its own, manipulating politics and events for its own labyrinthine schemes – in doing so, it often comes into conflict with its largest rival, Blue Sun.
Mitsui Shinkai: Originally a major banking corporation owned by descendants of the Japanese Imperial family, this megacorporation is headquartered on Sihnon, in the Japanese enclave city of Kita-Hirasaki. Mitsui Shinkai is a major producer of electronics, cybernetics, and military vehicles, in addition to finance and consumer products. They are also well known for their funding and support of traditional Japanese religion and culture, maintaining their cultural distinctiveness in the face of the homogeneity of the Anglo-Sino Alliance. Mitsui Shinkai is distinctive in that it has been a major corporation since Earth-That-Was, dating as far back as the 17th Century AD.
Orbus Space: Orbus Space is one of the largest transportation companies in the 'Verse, accounting for nearly 30% of all regularly scheduled air and space transport by themselves. Their sleek white and red transport vessels can be seen throughout the Core and Border worlds, though they are less common out on the frontier. Orbus Space also manufactures spaceship components and military equipment for conventional aircraft. They also dabble in finance through Orbus Bank and Orbus Financial, but this is strictly a sideline industry.
Rance-Feaney Informatik: A firm headquartered in New Surrey, Londinium, this company deals in information, security, surveillance, and certain forms of media. They maintain a completely neutral stance, and will supply timely, accurate information to anyone with the means to pay for it. Rance-Feaney Informatik is most notable as a source of information on nearly everything and anything. If they don’t know it, they can find it out. The company is well known for hiring freelancers, and will often pay handsomely for seemingly unimportant bits of information about nearly any topic – these unconnected pieces often go together to create a frighteningly accurate portrait of events in the 'Verse.
The economy of the 'Verse is dominated by the "Megacorps", corporations larger than any that existed in the 20th Century. Most got their start as state-run enterprises in the early years of the Sino-American Alliance, eventually being privatized once the economic situation began to improve. While most Megacorps are known for one or two primary lines of business, usually the one that they started with, nearly all have diversified extensively. The situation is further complicated by the mutually interlocking systems of ownership. The biggest dozen Megacorps each wield the power of an old-Earth nation state. In the Core Worlds, they offer their employees a de-facto alternative form of citizenship. Instead of being "Arielese", or "Londinite", or "Sihnonren", a person might regard himself as a "Magnus Citizen". This has both advantages and disadvantages, and really only applies to the largest cities on the Core Worlds. The Firefly setting already includes numerous corporations, such as Blue Sun, Gehornspiel, Iskellian Technologies, Weyland-Yutani*, and Allied Spacecraft Corporation. These are detailed elsewhere on the Internet. What follows is a list of the biggest, most influential, or simply best known Megacorps. Most of these do their business in the Core or the Border Worlds.