One thing I have been wondering about - speaking of changing URIs, did they (W3C) change/merge the domain name from w3c.org to w3.org at some point? Some old documents seem to point to w3c.org instead of w3.org. (e.g. http://www.w3c.org/2001/XMLSchema) Not that it hugely matters, the old (?) w3c.org links still work, since they are redirected anyway.

Example from a book: https://books.google.com/books?id=yLj8m3K0kNoC&pg=PA224&dq=h...