I put homemade, but actually it is a Greyhawk campaign that has been running since the folio was released, back in '83(?). It was running even before that, but we just used infor from the various books.
One hting we did though, and still do, is natural timeline progression. So, instead of it being 591 CY, it is more like 2500 CY. I cannot remember the exact conversion since we switched over to a new reckoning after the War of the Wizard Kings back around 800 CY.