Build 2014: Microsoft announces Windows Phone 8.1, shows off Cortana the digital assistant

At the Build 2014 conference keynote in San Francisco, Microsoft's Terry Myerson and Joe Belfiore have kicked off things by giving us more details about Windows 8.1 Update 1, and officially unveiling Windows Phone 8.1.

Windows Phone 8.1

The first part of the keynote was focused on convincing developers that the Windows Phone ecosystem, with the release of Windows Phone 8.1 this spring and the securing of more OEM partners, is finally ready to kick ass. Most of the features that Belfiore ran through we already knew about from previous leaks -- but we were treated to one cool new thing: Cortana!

Unlike Apple's Siri, which is something of a black box that you merely talk to, Cortana is much closer to Google Now. Basically, Cortana (yes, that's her name, much like Siri) sucks up as much information as you give it -- including your contact list, your email, your searches, etc. -- and then proceeds to act as an interactive, proactive digital assistant. You can also use Cortana like Siri, though, to set alarms, send messages, and so on.

You can also perform some very interesting contextual tasks, such as asking Cortana to remind you to ask someone about something the next time you talk to them -- so, the next time you phone your mom, Cortana might remind you to ask her about her herb garden, or whatever. Cortana can also hook straight into third-party apps, such as Skype and Facebook.

Cortana looks very fast and very slick. We'll be sure to update the post with our own hands-on impressions as soon as possible.

Belfiore showed off a cool new feature of Windows Phone 8.1, where apps can heavily customize the lock screen. The video demos made this new functionality look very cool indeed. We also got a closer look at the new notification tray -- one of Windows Phone's most-needed features.

Windows 8.1 Update 1

Belfiore also stayed on stage to demo some of the biggest changes in Windows 8.1 Update 1 -- most notably, the ability to interact with Metro apps from the standard Desktop taskbar. The Windows Store app will also be pinned to the taskbar by default, so that Desktop users can more easily discover Metro apps.

There still doesn't seem to be a way to launch apps directly from the Windows Store after installation (why??) -- but recently installed apps will now be highlighted on the All Apps screen, which is nice.

Hilariously, he noted that these Desktop-oriented changes (which many of us have asked for since the original Windows 8 beta two years ago) won't impact Windows 8's usability on touchscreen devices. Phew. Personally I've been using Windows 8.1 Update 1 for a couple of weeks (since the official update files leaked), and it's definitely an improvement for Desktop use. (Read: How to install Windows 8.1 Update 1 right now.)

The keynote is still ongoing (it's a three-hour behemoth that lasts until 2:30pm eastern time), and you can watch a live video feed on Microsoft's Channel 9 website(Opens in a new window). We'll update this post with more details as the keynote continues.