understanding freebsd development logic

[prad]

i am puzzled by what seems to be almost a parallel processor development
model that exists with freebsd. when 7 came out people were still
working on 6.3 i think it was with the aim of going to 6.4 and now with
7.x underway, there is work being do for 8 (for which you can get a
snapshot cd. (i seem to recall something similar with debian too).

why would people work on 7.x (and 6.x as well i guess) if 8 is already available?

is the idea to make each version 'as good as possible' because it would still be useful for older machines? or is it that later versions can utilize code from the earlier versions? or is it something else?

-- 
In friendship,
prad

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