With only two weeks to go before the release of OS X Leopard, the fifth major revision of Apple’s (AAPL) flagship Macintosh operating system, AppleInsider today published the sixth entry in its comprehensive Road to Leopard series — and at Apple’s insistence pulled two earlier posts offline.

Written by Prince McLean, the nom de plume of a systems programmer who clearly knows his stuff, the series not only describes with text and screen shots the key innovations coming in Leopard, but it takes pains to place them in the history of graphical user interfaces as they evolved from Xerox Parc, through Lisa and the first Macs, Systems 8 and 9, Next and the previous versions of OS X. The Commodore Amiga even makes a cameo appearance.

The series is so good that Apple’s legal staff has stepped in, demanding through cease-and-desist orders that parts of the first two entries be removed. AppleInsider has taken them temporarily offline while they are being redacted.

[UPDATE: The first two posts are back up in heavily redacted form.]

If you’re interested in what’s in store for you when Leopard finally arrives, you might want to archive the other posts before key sections disappear. Here are the links: