Origin Systems Incorporated

Origin Systems Incorporated, also commonly called OSI for short, was the name of the company that created and released the popular single-player Ultima series of games upon which Ultima Online is based, which itself was released in September, 1997.

OSI was acquired Electronic Arts in September 1992.

For more information, see here:

http://en.wikipedia.org/wiki/Origin_Systems

though of course remember that the Wikipedia, like UO Guide, can be edited by anyone, at any time, for any reason.