What version of FBSD does Yahoo run?

[TM4525 at aol.com]

In a message dated 10/8/04 2:42:11 AM Eastern Daylight Time, 
tedm at toybox.placo.com writes:
> Here is a thought.
> Why would they be running a pre-production release as a production 
> server????
> I have no idea what yahoo does, but I think it would be irrespondsible
> for them to attempt using 5.x on a production machine...
>

I'm sure that Yahoo, like any large commercial enterprise, has a whole
host of specific customizations that they have applied to FreeBSD,
and their version of FreeBSD doesen't look like what we have, at least not
where the good bits are.
 Why would they customize a "beta", knowing that they'd just have to redo them
when its released? I doubt they are that stupid. Also, If they've done 
substantial
customization, then you really need to stop touting them as "using FreeBSD", 
don't you, since they are not using whats available to everyone else.