SAN FRANCISCO—Windows 10 was the focus of Microsoft's day one keynote at its annual Build developer conference. Today, the company announced an update that'll ship this summer called the "Anniversary Update."

The company led by talking about the adoption of Windows 10. After its first eight months on the market, there are now 270 million Windows 10 users. This is immensely fast for a new Windows version, with Microsoft claiming that Windows 10 adoption has outpaced Windows 7 adoption by 145 percent.

Still, Microsoft has a long way to go to hit its target of 1 billion Windows users within two years of launch. Windows 10 will continue to be a free update for Windows 7 and 8 users for another 4 months, after which time anyone on those operating systems will, in principle, be required to pay. We can well imagine that Microsoft will extend the promotion in some way, but the company hasn't announced any plans to do so just yet.

The Windows 10 Anniversary Update will be the second big update (the first being last year's November Update) for Windows 10 "as a service". True to Microsoft's vision of having one Windows operating system that'll be available for PC, tablet, phone, HoloLens, and Internet of Things devices, this update should be available for all of those platforms... and one more: the Xbox One.

With the Anniversary Update on Xbox One, apps built for the Universal Windows Platform, the core set of sandboxed and modernized APIs that spans the entire range of Windows variants, will be able to run on the Xbox One. The same Windows Store will be used for all apps, and any developer will be able to use their console as a development kit to test software for the living room. This update will also enable Cortana on the Xbox One; she was included in some beta builds of the major dashboard update that was shipped last year, but didn't make the grade for shipping. This summer, she should.

UWP games have come under particular scrutiny recently, with complaints about mandatory v-sync, difficulties supporting multiple video cards, and Epic's Tim Sweeney fretting about Microsoft creating a closed platform. While many of Sweeney's misgivings appear to be unfounded, Microsoft is nonetheless making changes to make UWP better for a wider range of games, and the Anniversary Update will enable games to disable v-sync and better support multiple GPUs. This leaves support for end-user modifications as the major remaining technical sticking point, though Microsoft is certainly aware of the demand.

Keen to further drum up the number of apps in the store, Microsoft announced at last year's Build Project Centennial a way to wrap up and package existing Win32 and .NET applications and ship them through the store. The company has remained weirdly quiet about this since that announcement. It seems that apps packaged this way will offer the clean installation and uninstallation that regular Store apps boast, but without the full sandboxing and restrictions of UWPs, using technology similar to the App-V app virtualization that Microsoft already offers to enterprise customers. Centennial is also finally going public, with Microsoft shipping a converter tool today to allow developers to package their existing Win32 and .NET apps so that they're suitable for Store distribution.

The Windows Store itself is getting a new section to promote apps that offer Cortana integration. In the Anniversary Update, Cortana is going to become smarter about proactively taking action on your behalf, such as offering to buy your lunch or send e-mails that you promised to send (let's hope she doesn't take after her ill-behaved millennial cousin). Third-party applications will also be able to offer their own deeper Cortana integrations, allowing their apps to respond to the inferences that Cortana has made.

Similarly, the Windows Hello biometric authentication system is being extended to allow biometric authentication to websites.

Finally, and most surprisingly, the Anniversary Update will support the use of the popular bash shell on Windows. But not merely some port of the bash shell. An actual Linux program, with all the other command-line tools that people expect on a Linux shell. There's still a lot that Microsoft isn't saying about this (or at least, not yet), but we felt it was a big enough deal that it needed its own post.