The 95 line is in there because someone mentioned it. The MS numbering does make sense. After 3 there was 95 so it gets 4, and the rest were incremental updates worthy of a dot release. 2000 was a big change from NT, so got a whole number, while the incremental changes of XP and 2003 got dot releases. Vista was a big change from XP (good or bad), so got a new number, with 7 getting a dot.
I am among those who isn't happy that the original 7 project didn't come through. I was expecting that complete rewrite with the MinWin kernel, but just got a dot release over Vista.
MS numbering doesn’t make sense, that’s why they keep changing. First they did version numbers, then they went to years, then they went to goofy names, now apparently they’re going back to version numbers, unless 7 is just a goofy name.
Part of the problem is there were 2 lines (the 3.x code and NT code had little to do with each other), then they merged (XP uses the NT kernel), but even after the merger they still maintained a separate identity. You say 95 was 4 then 2000 get’s its own number, but 2000 is in the NT line and there was NT4, which still leave 2000 as 5 but not of the 3.x/95 line.
I’m among those who isn’t happy the original Longhorn project didn’t come through. Jettisoning downward compatibility would have done wonders for he OS.