What is the longest running computer RPG franchise?

Since I find all my answers to my questions on Google or Wikipedia, I figured I’d ask something I knew the answer to – just to see if anyone gets it right. Like a game show.

What is the longest running computer Role-Playing Game (RPG) franchise, and possibly the longest running game franchise of all time?
UPDATE: It is not Metal Gear; that is a stealth action series.
Tibia was released in 1996; more than a decade after the first installment of the longest running RPG series.
Resident Evil is a surivival horror series, not an RPG.

The Legend of Zelda is old, but not old enough

The Forgotten Realms games began as pencil-and-paper, and didn’t enter the realm of computer games until the late 80s; a few years short.
Silent Hill is not an RPG.
WINNER! I have to wait 4 hours to choose the best answer, but "sgoldperson" is correct; the Ultima series is the longest running RPG franchise, beginning in 1979 with ‘Akalabeth’ to the present, with Ultima Online.

I’m so happy nobody said Final Fantasy; I don’t consider it an RPG.
I consider Final Fantasy a Turn-Based Strategy Game that follows a cast of characters. To see my rant about my Final Fantasy aversion (if you’re really interested in anything I have to say), go here:

http://mannpower.livejournal.com/31939.html