Over on Canonfire I found this cool article An Alternative Linguistic History of the Flanaess written by someone identified only as Ullmaster [EDIT 12/21/16: Actually, Ullmaster is just the dude who uploaded the post, Joe Chevalier is the actual author of the piece.]. If you're a Greyhawk weirdo like me then you'll find that it's definitely worth your time. Here's a highlight:
"I subscribe to the theory that they arrived on Oerth from another world, and brought their language with them." Ullmaster, An Alternative Linguistic History of the FlanaessAnyone who remembers my bit on the Oeridians being extraterrestrials based on linguistic and spaceship-crash site evidence will think I've found my soulmate here, except that the "they" that the author is referring to in this case is the Olman people who occupy the jungles to the south of the Flannaes, not the Oeridians. Ullmaster, offers no justification for why the Olman (Olmen?) might be from a galaxy far, far away, and yet by his very name he should know damn well that the Oeridians landed their starfleet in or near Ull some 1200 years ago. As the Oeridians are very secretive about their origins, it's only natural that Ullmaster--indubitably an Oeridian himself--is trying to deflect attention from UFO seekers to a point as far from Ull as possible.
To further demonstrate the lengths to which the Ullmaster is willing to go to mask Oeridia's true origin, s/he has this to say:
"Oerid: This people came from a land to the northwest of the Suel, in a coastal land ruled by dragons."Only by tacking the words "and unicorns" to the end of that sentence could it be made into a more blatant fabrication. We're on to you and your alien-people, Master of Ull.
All kidding aside, it is a pretty fascinating read wherein the author compares Greyhawkian languages to earthly ones. I highly recommend it.