Windows 8 and Windows Phone 8 together mark a rare confluence for Microsoft: they represent the first instance of the company's desktop and phone platforms sharing the same browser base, and that has wide-reaching implications for what developers can do. The Redmond team doesn't want anyone plunging headlong into web apps without knowing what to expect, however, and it just reminded us in a blog post that there are still a few off-limits areas for Internet Explorer 10 on the mobile side. Not surprisingly, elements that demand a truly big screen or a windowed interface won't fly -- there's nowhere to drag-and-drop from or open a new window to. A few other aspects are more likely to catch web developers off-guard, such as the lack of in-line video, a handful of touch inputs, ActiveX and the level of file access. The most important common ground stems from simply having a modern rendering engine whose HTML5 and CSS3 support will prevent any rude shocks. There's much more at the source link, although Microsoft and designers may just be happy that any Windows Phone web development is a question of finding those few things that won't work, rather than reinventing the wheel.