I know font rendering is very tricky and it will be different between browsers and operating systems (eg. Firefox and Chrome will render differently on Windows) but what I puzzled about is how the same browser can render HTML/CSS differently on two different operating systems.
I just installed Firefox 18 on Linux x86_64 and Windows 8 and the Outlook.com website is completely broken on Linux. Fonts look different, sure, that's not the problem. The problem is DIVs are overlapping, images are misplaced, etc.
Of course it's just this website and it could be the one to blame. Any other idea why HTML/CSS would render different in Linux and Windows? Different extensions being enabled? I don't have any plugin messing with websites.