That's the University of Oxford, but the term "Oxford comma" is a reference to the Oxford University Press. As you can see at http://www.oup.co.uk/academic/authors/AuthorGuidelinesMain/H... the OUP does require the use of the Oxford comma.

I think that's because the term "Oxford comma" is somewhat of a misnomer. The comma before "and" actually seems to be more preferred in the United States that in Britain.

"Opinions vary among writers and editors on the usage or avoidance of the serial comma. In American English, the serial comma is standard usage in non-journalistic writing that follows the Chicago Manual of Style. . . . It is used less often in British English,[5][6] where it is standard usage to leave it out, with some notable exceptions such as Fowler's Modern English Usage."

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

I prefer to use oxford comma where I'm writing a long list of items, and those items contain sets within themselves.

For instance, while listing computer brands that include Dell, HP, Acer, Toshiba, Alienware, Compaq and ASUS, I wouldn't use the oxford comma. But if I'm listing out speaker brands like Bose, Klipsch, JBL, Bang and Olufsen, and Altec Lansing, I think oxford comma helps to clarify the meaning intended.

relatedly, there's a little-used rule that lets you use a semi-colon as your list separator if the individual elements contain commas: "My favorite law firms are Dewey, Cheatem & Howe; Robinall, Widowes, & Laffin; and Sue, Grabbitt, & Runne."

But the Chicago Manual of Style encourages its use - this isn’t a closed book. Which the wikipedia article points out.

In one case I discourage it as well, because with it you can't write the funniest sentence ever composed: "I would like to thank my parents, Ayn Rand and God."

Otherwise, no strong opinion, although I usually use it myself.

And here's a classic joke that works best with the serial comma:

"There are two hard problems in computing: naming things, cache expiration, and off by one errors."

The comma indicates a pause when spoken, and you need that pause in this particular joke.

On the other hand, with the serial comma you get "I would like to thank my mother, Ayn Rand, and God."

True! And it's also very funny. (But a shade less so than the parents sentence.) Maybe our descriptivist/purist friends should start a campaign to bring back the dative.