Platform transitions are hard, moving from silicon to silicon or operating system to operating system. But there’s one thing that’s harder: moving from one SDK to another. Microsoft is in the middle of a massive transition, away from more than a decade of Win32 code and its various user experience layers to the modern WinRT and Universal Windows Platform (UWP).

That’s a huge project, with billions of PCs and Windows installations of all versions, and with code that’s built using raw Win32, with WinForms, and with WPF. Porting it all to UWP overnight is an impossible demand on an industry that’s focused on supporting existing line-of-business software with only incremental upgrades. And although Microsoft’s Desktop Bridge allows some integration with Windows 10 features, it doesn’t bring them back to software written for Windows 7 or take advantage of new user interface components that have no equivalents in older Windows SDKs.

Improving the UWP desktop UI

With much of the work on delivering the core UWP platform complete, Microsoft is now working on ways of back-porting its features to older SDKs, with the aim of bringing what it calls “modern applications” and desktop applications closer together. Part of that process is a new set of UWP controls that’s more desktop focused, along with ways of embedding those controls in older code and with new deployment models that make it easier to roll out new versions of older applications.

UWP’s window layout inherits much of its control design and spacing spacing from the tablet-first Windows 8 WinRT. With Windows 10’s focus on desktop applications, that’s led to applications with a lot of wasted screen real estate. What might have worked well on a single screen on an 8-inch tablet doesn’t work on a 28-inch monitor, let alone on a 15-inch laptop. If you compare Windows 10’s bundled Mail app with Outlook 2016, you see how much information is lost in UWP layouts.