Microsoft just did a really smart thing by bringing Windows 10 to a $35 PC

On Monday, Microsoft announced that it would be giving away a free version of Windows 10 for a new, tiny $35 computer known as Raspberry Pi 2.

This is a quiet but important announcement that shows just how much Microsoft has changed under Satya Nadella.

Raspberry Pi is a hugely popular little PC - it's really just a tiny circuit board with a main processor (a CPU), a bunch of memory, and the plugs that let you hook it up to input/output devices like a HDMI video.

Until now, it has always run Linux.

The small computer is a favorite with the "maker" crowd, those people who tinker with electronics to build fun and crazy stuff (home grown versions of Google Glass, electronic penny arcades, musical vegetables ...).

But at $35 apiece, it's also an extremely popular platform for "Internet of Things" apps, the trend where sensors are embedded into ordinary objects, operated by apps, and accessible over the internet.

This is the first time Windows has ever run on Raspberry Pi and what makes that especially noteworthy is that the new Raspberry Pi 2 is not powered by an Intel processor, but by Intel's competitor, ARM.

The only other ARM version of Windows was Microsoft's failed tablet platform, Windows RT, which was an offshoot of Windows 8. Windows RT only ever came out on a handful of devices, and PC makers abandoned it pretty quickly, leaving Microsoft's Surface tablets as the only Windows RT tablets.

Then, Microsoft confirmed it would kill Windows RT at its Windows 10 press conference when it said that RT would not be updated for Windows 10. Microsoft has also stopped selling the Surface 2, the last tablet to run Windows RT.

That news left people wondering if Microsoft would drop ARM support altogether, and stick by its decades-old partnership with Intel.

But ignoring ARM altogether would have been bad for Microsoft. ARM is the processor of choice for mobile devices, including many IoT devices, because its easy on the battery. IoT is an up-coming market expected to generate billions - maybe even trillions - of revenue in the next decade.

The Raspberry Pi news means that Microsoft found a newer, and smarter use for its ARM version of Windows

than an unloved tablet.

And it also means that CEO Satya Nadella's promised that Windows 10 would be a developers dream, running on all sorts of devices from tiny IoT things to giant video screens was for real.

And that's the single most important thing that can save Windows, getting developers excited enough about Windows 10 to write cool new apps for it.

Here's what Eben Upton, Raspberry Pi CEO and founder said about Microsoft when announcing the new version of Pi:

For the last six months we've been working closely with Microsoft to bring the forthcoming Windows 10 to Raspberry Pi 2. Microsoft will have much more to share over the coming months. The Raspberry Pi 2-compatible version of Windows 10 will be available free of charge to makers.