An offshoot of the new movie is the Weyland Industries site. Weyland created the androids Ash and Bishop as well as the (alarmingly unstable) atmosphere processors from Aliens, and apparently a great many other innovations for space travel as well. In cut scenes from Aliens you see their logo on the colony buildings. Otherwise, the company is never actually mentioned by name - it's the ubiquitous "Company" in both the first and second movie, represented by the bland Ash and blander Burke and their nefarious plans.
(In a cool bit of metamoviemagic, the URL www.prometheusmovie.com redirects to the Weyland Industries site.)