As others have said, if backwards compatibility was a claimable issue, Microsoft would be out of business by now.

The only way that Microsoft (or any other organization) would be liable for this would be if they contractually agreed to such a constraint. And, having been working with Microsoft’s agreements for over a decade, I can tell you without a doubt that they don’t have this in their template (and that they don’t come too far “off” their template, even for REALLY big deals).

The net-net on this is that unless there’s a larger agreement in place (for example, if Microsoft has an agreement with the W3C to keep IE compliant with the standards), Microsoft has ZERO liability (of any sort).

Oh! That’s not how I read it at all, though your second question (that I deliberately glossed over here) should have tipped me off.

The ‘I am Not A Lawyer’ and in particular ‘I Am Not Your Lawyer’ disclaimers apply in full bloom here.

First, all of the things above should apply to you. As long as you’ve made no special deals with particular customers, you’re probably in fairly good shape. The rest of the industry would surely join in supporting you if a case came to court.

Second, I’ve never seen or heard of anything cases like this, though admittedly have not looked hard for it nor taken any applicable courses.

Finally, you’re not selling anything, so even if there were court-created liability, it isn’t clear what kinds of damages you’d be liable for. Courts are still fairly sensitive to ‘get what you pay for’-style arguments, and I have to imagine they’d be particularly sensitive in the FLOSS context. So it is entirely possible a court could say ‘Mozilla is liable… for a zero dollar penalty.’

But yeah… definitely recommend talking to Your Lawyers about the question before one goes about blithely relying on my opinions on this. Vast difference on my part between saying ‘you should be suspicious of another party’s claim’ and ‘hey, you’re fine, don’t sweat it!’

I was mostly wondering if this is a concern that Mozilla or other browser developers should have as well — if Microsoft has created their own liability through custom contracts, as you say, then that’s their unusual bed to lie in, and not a burden that should be imposed on the rest of the process or industry.

Karl: if you’re trying to deal with someone in good faith, you sort of have an obligation to not get them sued if you can. I think implicit in Shaver’s question was ‘is Microsoft dealing with us in good faith’ or ‘do we need to deal with them in good faith’; you can draw your own conclusions on that after this post.