2009/7/7 Samuel Klein meta.sj@gmail.com:
Once a name or monument transcends what it originally named and is used by reference to describe similar things elsewhere, there is a tendency to add the definite article -- the Earth, the Sun, the Sphinx, the Oracle, the Colosseum. I do see people running wikis of any sort on their own or their company site, with a comment that they have 'set up their own wikipedia'. This would be consistent with calling the original Project 'the' Wikipedia.
That's common usage, which we're trying to drive back out by pointing out that's a trademark and "wiki" is the generic term ;-)
Of course, then you have people using "wiki" to mean "Wkipedia" ...
- d.