The main point behind this site, as I see it, is to replicate iPhones UI. I share the same opinion as yourself and Peter in that we shouldn’t be going down the route of creating platform-specific sites; instead, as Peter pointed out, developers should be building interfaces designed for a wide array of mobile browsers. However, I think we need to define a ‘platform-specifc UI’; I think it’s a bit over the top to try and match colour palettes/gradients to a specific UI, but instead I feel that the design be brand-focused. If Facebook however were using fundamental CSS properties (same could apply to JS) that were specific to WebKit, which in turn meant that the site broke in other browsers, then as far as I’m concerned, that would be going down the wrong path.

Regarding your comments about the use of WebKit specific rules, if or when vendors such as yourselves are allowed to develop browsers for the iPhone, that the devs at FB will update their CSS accordingly – as I’ve already mentioned there is at least one instance of ‘-moz- in there somewhere, so they’re obviously anticipating that browsers other than Safari will be or are already using the site, and why include the standardized ‘box-sizing’ property if Webkit only support their own vendor-specific extension?

I’m also unsure as to what you mean when the site will break in Mobile 9.5? So far as I’ve seen, ‘box-sizing’ is probably the most crucial layout property that is used and as I’ve mentioned already, they’ve included this in the form of the standardized property (which Opera supports) in the stylesheet. As to the other Webkit-specific properties; I’m guessing they’ve added these either because the property itself isn’t stable enough to be implemented at this stage, therefore sticking to their own version of the property makes sense for the time being, or purely for the progressive enhancement aspect (border-radius, border-image).

Edit
@David, I’d also be very interested to hear more about this iPhone quirks mode you speak of?

Opera Mobile should in theory be able to render the iphone site, but the URL is illogical for none iphone users to use, instead they will get the really stripped down m.facebook. Also the WebKit specific rules means Opera wouldn’t get those styles, even when we support them, and some we do not support, so it will break in Opera Mobile 9.5. You could say that Opera should support them, but Opera already has good CSS3 support obviously, and they are not using CSS3 that Opera supports but Safair doesn’t. It is kind of strange they’ve taken Mozilla into account when they only have a paperware mobile browser, and not Opera when we have mobile browsers shipping on hundreds of millions of devices. The sooner iphone.* sites die out the better. We in fact had to add a iphone quirks mode of sorts to Opera Mobile due to this issue of designing for one browser AND one device.

On the grammar side, I’m a pedant without a cause. When I see “it’s” when it’s not an abbreviation I die a little inside.

With regard to the subject of the article, I know what you mean – I was writing a JavaScript application to help me learn the language. It felt good to be able to ignore IE’s (lack of) standards compliance since I was using Opera.

Please accept my apologies for the harsh comments…please?

As I haven’t yet seen a site which includes a substantial Media Queries implementaton, iphone.facebook.com is a chance to see a vast array of l3 features implemented, and was intended as a ‘live example’. As I’ve mentioned before Safari is the sole browser on the platform (I daren’t ever mention the i-word from now on, in fear of being labeled a fanboi by your good self) for the time being. If Opera Mini for example, was shipped as the default browser in another popular mobile device, and a brand as large as Facebook decided to create a site specifically for it (with a similar volume of CSS3 features), then I would have obviously written about that- this of course isn’t the case today.

And yes, I am the verge of becoming an Apple fanboi- I have an iPod and a MBPro (I would personally use a Mac over a PC anyday), but I’m sure everyone knows that that beared absolutely no weight when I was writing the post, except for you for some reason.

Thanks also for highlighting my two grammatical errors – they’ve now been corrected :)