Why use Warranty Disclaimers?

[Chris Travers]

On Sun, Dec 5, 2010 at 6:22 AM, Oleksandr Gavenko <gavenkoa at gmail.com> wrote:
> Most OSI approved licenses contain Warranty Disclaimers.
>
> 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?
>
> As example how I think: I make bench near my house
> so it's free to sit by anyone. But some heavy man
> sit and fracture his leg because bench work only
> for 100 kg. I don't promote to sit but I don't
> warn about 100 kg limit.
>
>
IANAL but here is my understanding.  It's not the same issue as the
bench issue at all.  Warranties in common law jurisdictions like the
US are creatures of contract.  The bench is a very different question.

The basic reasoning is that when you sell or otherwise distribute a
product you are representing that the product is, among other things,
fit for the use for which you are selling it.  If I buy a coffee cup
from you that you advertise as a coffee cup, I expect that it isn't
going to melt when I put hot water in it.  If I buy a hammer, I expect
that it won't shatter when I try to pound a nail, etc.  So I represent
that a product is fit for a use, and you buy it on that basis.  In
essence these are elements that are assumed to be a part of the
purchase contract.

Now, without a warranty disclaimer, some implied warranties (i.e.
representations regarding the product) are assumed to be made when the
product is distributed.  These include the representation that it's
fit for a particular use, that it conforms to an ordinary buyer's
expectations, and so forth.  Based on these expectations you buy the
product.  If these are not the case, then the purchase transaction is
invalid at very least.  Presumably damages could be awarded beyond
purchase price in at least some cases.

What a warranty disclaimer does is it clarifies how you are
representing the program.  You are no longer saying you guarantee that
it meets, for example, the expectations of an ordinary buyer, of that
it is fit for a specific use.  Instead you are saying "try it and see"
(which is particularly apt for software that you are getting for
free).    This avoids the argument that you gave this software in
exchange for something (viral marketing, or whatever might possibly be
as weighty as a peppercorn in terms of consideration), and that the
product did not conform to expectations, and hence you violated the
contract with the downloader.

Best Wishes,
Chris Travers