As we covered just yesterday, a leaked build of Microsoft's upcoming Windows Blue (aka: Windows "8.1") is floating around the net "somewhere", and as it appears, there's quite a bit that has changed. No, we didn't get rid of the Start screen, but many further enhancements have been added, along with other niceties around the OS.
Neowin wasted no time in exploring the latest build, and in doing so discovered a subtle but extremely notable tweak that Microsoft has conducted with Internet Explorer 11. It's no secret to anyone by this point that coding a website to support older IE versions is a pain - even Microsoft itself acknowledges this. However, things still are not perfect, and for that reason, IE 11 in Windows Blue impersonates Mozilla's Firefox. By doing this, a website using IE-related CSS workarounds wouldn't deliver these workarounds at all, but instead the page as it would be delivered to Firefox.
With this move, it's clear that Microsoft is tired of hearing about users who are having a difficult time viewing a webpage in its Web browser. Even today, equipped with IE 10, I haven't been fond of how the browser renders fonts, but that's a minor niggle. More serious issues have included login boxes not functioning properly or page elements in general - both rare occurrences, but I don't exactly use the browser on a regular basis.
For Microsoft to actually impersonate a competitor's browser is pretty wild, and it'll be interesting to see what Mozilla has to say about it. We can also likely glean that Microsoft chose Firefox over Chrome to impersonate as its Trident engine likely mimics Gecko's rendering engine better than WebKit.
Of course, Windows Blue doesn't even have a release date yet, so there's no telling whether or not this User Agent will remain like it is in the final version. I truly can't see it happening, because impersonating another company's product is a step that wouldn't be taken lightly.