matticus008 said:However, if you count Windows 2000 (released in '99) as the beginning of the current family, you see a new OS every two years (2k, XP, 2003, Longhorn [originally supposed to be out by now]), as opposed to the three retail versions of OS X since 2000 (10.0, 10.2, 10.3).
Well, FWIW, you are comparing different things there. All version of OS X you listed ares OS'es meant for the end-user. On the Windows-side, W2K, XP and Longhorn are such OS'es, but 2003 is a server-OS. You could say that it's the server-version of XP. For users who run XP on their desktop/laptop, Windows 2003 is not really relevant at all. The people who would be interested in 2003, are the ones who run W2K-based (W2K had both client and server-version) server-system.