So many repo formats

[David Ingamells]

Matthieu Moy wrote:
> Gour <gour at mail.inet.hr> writes:
>
>   
>>>>>>> "Matthieu" == Matthieu Moy <Matthieu.Moy at imag.fr> writes:
>>>>>>>               
>> Matthieu> But AFAIK, WinXP is still able to execute 15 year-old MS-DOS
>> Matthieu> binaries, And MS supports each of their OS for at least 5
>> Matthieu> years.
>>
>> Hmm...
>>
>> Matthieu> So I don't think the analogy plays in favor of breaking
>> Matthieu> compatibility.
>>
>> Lot of DOS programs cannot work any longer on modern CPUs...
>>     
>
> How many years happened between the birth of these programs and the
> time they were no longer executables?
>
> (to be compared with the age of bzr, which is IIRC < 4 years)
>
>   
>> Otoh, e.g. there are GUI programs on e.g. WinXP which do not work by
>> going from one SP to the other...
>>     
>
> Usually, this is because they relied on bugs which have been fixed. MS
> used to work a lot on bug-to-bug compatibility, but it seems they
> consider it less important now. And that's really part of their
> success, because the old CD that a friend of a friend burnt years ago
> still contain stuff that you can use on your PC. And that's also part
> of Vista's failure : most people don't like it because it doesn't run
> their old software or device.
>
>   
This is all irrelevant to the thread, since the comparison is between 
apples and oranges.

Microsoft has a very different business model (when compared to open 
source) for OS's where it is in their own interest to have built-in 
obsolescence.

If you wish to use MS for the comparison then a better comparison is 
with MS Word, the latest incantation of which still (AFAIK) can still 
read format 1.0 .doc files from 198x written with the very first version 
of MS Word.