[Jamiecon]

The huge number of hooks that Windows provides to third party developers is both its blessing and its curse. I highly recommend Raymond Chen's blog for a (often hilarious) description of this world.

AFAIK, Windows 8 takes interoperability further with new features like intents, while still offering the full Win32 API (on x86 builds).

Play / pause controls are a good example. Applications have been able to integrate via global hotkeys since.. Vista? Maybe XP. Either way, I am still able to control Spotify on my Win8 laptop using the hardware controls. As I would be able to with any application that chose to implement support.

Windows continues to be the only OS to provide this kind of deep out of the box support on a broad range of hardware from multiple suppliers.

Edit: grammar