Microsoft launches Windows 10 Technical Preview for Phones

The chances are that you have tried out Windows 10 on your computer already and now -- at long last -- you have the opportunity to try it out on your Windows Phone. Windows Insiders can now grab the first public build of Microsoft's latest mobile operating system and try it out for themselves.

Windows Insiders have been eager to see what Microsoft has done with Windows Phone, and earlier today Gabe Aul cryptically hinted at when the first build would be released. Now it has gone live. As with all preview builds, this is far from a completed product, and there are a few caveats to bear in mind.

First of all, there are a very small number of handsets that are eligible to use the preview for now. In fact, there are just six: the Lumia 630, Lumia 638, Lumia 635, Lumia 730, Lumia 636 and Lumia 830 -- but, pleasingly, the preview is available internationally. There's no mention of some of the big hitters like the Lumia 928, 929 and 930 at this stage. If you're wondering why more high-end phones are not included, Microsoft has an explanation:

We have a feature that will be coming soon called 'partition stitching' which will allow us to adjust the OS partition dynamically to create room for the install process to be able to update the OS in-place. Until this comes in, we needed devices which were configured by mobile operators with sufficiently sized OS partitions to allow the in-place upgrade, and many of the bigger phones have very tight OS partitions.

The second thing to keep in mind is that -- as the company points out -- this is the earliest ever public preview for Windows phones. Just as with Windows 10 on the desktop, Microsoft is looking for feedback but warns Windows Insiders that:

You will encounter bugs. You will see experiences that are clearly just not done yet, and UX that lacks polish at this point. DON’T WORRY! It will improve as we go and new features, stability and performance improvements, and more polished UX will come at each step.

So what's new? In addition to a (somewhat) seamless experience when moving from the desktop to a phone handset, and the ability to work with universal apps on both platforms, Windows 10 Technical Preview for phones boasts:

• Full-size Background Image for Start: We believe phones should be intensely personal -- so we’ve added another option to customize the start screen with a full-size background image.
• More Quick Actions in Action Center: We’ve increased the number of quick actions available to you. Windows Phone 8.1 has four programmable quick actions -- but with Windows 10 you also get an expanded view that can now have up to three rows.
• Interactive Notifications: Notifications are now interactive, allowing you to take action directly like dismissing an alarm, or seeing images for maps. For example, for text messages, when the toast pops, you can quickly reply inline via text or voice.
• Significantly enhanced speech-to-text capability: You can talk to virtually any data field you choose. Your words show up as you speak them – and punctuation appears automatically.  This feature is smart enough to understand when to use 'two' -- the number -- instead of 'too' as in 'also'.
• More powerful Photos app: From your very first launch, Photos will show the aggregated set of all your local photos and all your OneDrive photos

There's a lot missing at this stage, and there's clearly a lot of work still to do, but this is the preview that people have been asking for. There are a lot of known issues, but they're being worked on, and new builds will follow in the coming weeks and months.

Introducing this first build in a blog post, Aul explains how to get hold of Windows 10 Technical Preview for phones:

• Join the Windows Insider Program
• Register your device to receive builds as over the air updates
• Builds will come to you automatically as they are ready, after being validated by engineers at Microsoft and used on their own phones
• Use the built-in Windows Feedback app to send us problem reports and suggestions
• Updates will continue all the way up to the final build that goes out to all customers
• You can roll your phone back to the previous OS any time you'd like

So... fire up your Windows Phone and head on over to the Windows Insider website. Joe Belfiore shows off some of what you have to look forward to in a specially-produced video: