Why use Warranty Disclaimers?

[Ben Tilly]

2010/12/7 Dag-Erling Smørgrav <des at des.no>:
> Oleksandr Gavenko <gavenkoa at gmail.com> writes:
>> Suppose I put my code without Warranty Disclaimers into web and don't
>> sell/promote/advertise it and some one use it.
>>
>> Then this person can damage me in judgement?
>
> In the civilized world, no.  In the US, yes.

I believe that the US gets this from common law, which makes me wonder
whether similar things are true in much of the English-speaking world.
 (However the USA is more litigious, so it would be a bigger issue
here.)

See http://en.wikipedia.org/wiki/Implied_warranty for some general
background.  Although I'm admittedly unclear on how getting something
for free would qualify as a sale.