"Free" does not mean "GPL" only. If OSX were released under any of the many free licenses it would be fine, but sadly it is just proprietary software with some free components.

Well, to get picky about it, I believe the exception is that it's ok to use it while a non-closed alternative is in the works. I think the example Stallman uses in his talks is that of software controlling a life saving medical device.

Obviously the use case in point doesn't come under that though. :)

Makes me wonder why they have compatibility shims to allow their website show in browers like IE6...

Yes, it's pedantic, but this GNU we are speaking about.

That would actually make sense. It might help more people see the light.

Really? You think if I recommend emacs to someone using IE6 and they go view the site and it fails to display, that will somehow make them 'see the light'? I suspect the complete opposite is true and, hence, why gnu support browsers that aren't 100% GPLed.

Nobody is saying that it is practical, but GNU aren't known to make their stance on practicalities alone. GNU are known for their ideological purity, and a lot of people (some even quite grudgingly) admire them for their consistent stance.

I'm sure they've addressed this very issue. They almost certainly just write to the standards and don't bother putting in any browser-specific hacks, which is pretty much the best way to do things anyway, IMHO.

I saw at least one IE6 specific hack in their pages.

You seem to be in agreement with the person you're replying to. They're saying that there's a compatibility shim so that more IE6 users can 'see the light'.