What is it about two-digit version numbers?
Mac OS went up to 9, and now it’s Mac OS X. Everything since then has been numbered “under the hood.” You can find 10.3 in the fine print, but everywhere else it’s Mac OS X Panther.
Windows alternates between vintages and letters (Me, XP, etc.). Even then, they’re only up to 5.2 internally (Longhorn will technically be Windows NT 6.0).
Red Hat Linux got up to 9, then spun off into Fedora Core, starting over at 1.
Mandrake got as far as 10.1, and Conectiva to 10, and the merged system is moving to yearly vintages.
SuSE is about to hit 9.3, but Novell has been busy absorbing all the Linux companies they bought. It wouldn’t surprise me at all to see them release Novell Linux 1 instead of SuSE Linux 10.