Windows Phone 8 will run WP7 apps

Windows Phone 8 is an inevitability, but it has been one that many users have been unsure of. Due to the probable change to the core of the operating system, there have been doubts of whether it will remain cross-compatible with apps. A tweet from Microsoft's Director of Developer Experience has confirmed it, as WPCentral confirms.

For anyone who missed the Mix11 keynote, some videos of it have been preserved here. Brandon Watson is Microsoft's Director of Developer Experience for Windows Phone, so his response can be taken to be the truth. Speaking technically however, it is unclear how Microsoft plan to make it work. If Windows Phone 8 boasts a higher resolution it will be odd to see how apps work, and whether they zoom in to be used or not. That in itself could be problematic for developers of Windows Phone 7 apps.

On the plus side, transitioning the apps may not be extremely difficult since they make use of Microsoft's SilverLight. This means that they could theoretically be ported very quickly, if they were not cross-compatible already. What is known of Windows Phone 8 at the moment is only that it may use the codename of 'Apollo'. The current version, at the time of writing is Mango, and it is scheduled to be updated to Tango in the future.

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I'm sure he is referring to Windows Phone 8 but is there any chance that "next major Windows version" refers to Tango and not Apollo?

gcastner said,
I'm sure he is referring to Windows Phone 8 but is there any chance that "next major Windows version" refers to Tango and not Apollo?

Tango is a minor update, like NoDo. Apollo is the codename for WP8

If you report news from that area of expertise for years, and even wrote a goddamn book about Windows Phone development, how can you be so goddamn dumb as to how WP8 could or would support WP7 apps?! Thurrott's talking about emulation layers and virtualization. Foley's on Twitter yapping about recompilation.

Christ, bunch of idiots.

WP7 apps are compiled in an intermediary code format, of which one purpose is platform independence. And if the Silverlight runtime or a .NET runtime respective Phone assemblies is available, they'll run just fine.

Superluminal said,
If you report news from that area of expertise for years, and even wrote a goddamn book about Windows Phone development, how can you be so goddamn dumb as to how WP8 could or would support WP7 apps?! Thurrott's talking about emulation layers and virtualization. Foley's on Twitter yapping about recompilation.

Christ, bunch of idiots.

WP7 apps are compiled in an intermediary code format, of which one purpose is platform independence. And if the Silverlight runtime or a .NET runtime respective Phone assemblies is available, they'll run just fine.

As a journalist, it is never wise to assume anything.

dagamer34 said,

As a journalist, it is never wise to assume anything.

If that was the case then 90% of the news would cease to exist because all of it is based on connecting some dots and using your expertise to fill in the blanks. If reporters said nothing until the official press release was out (aka. the point where they're no longer making assumptions based on rumours/speculation/educated guesses) then what would be the point of having reporters?

NOT SO QUICK. Windows Phone 8 is rumored to be using the WinRT not silverlight Runtime. Now, while this is also based on .Net it doesn't have the exact same API's. So my guess is it will in fact use an API translation layer (similar to WOW 64). My guess is this is only a tempory measure and will not carry over to Windows Phone 9 (If they haven't fully merged by that point) as people will want to write code for WinRT API set so that it is compatable with Windows 8 Proper (Metro UI).

evilsushi said,
NOT SO QUICK. Windows Phone 8 is rumored to be using the WinRT not silverlight Runtime. Now, while this is also based on .Net it doesn't have the exact same API's. So my guess is it will in fact use an API translation layer (similar to WOW 64). My guess is this is only a tempory measure and will not carry over to Windows Phone 9 (If they haven't fully merged by that point) as people will want to write code for WinRT API set so that it is compatable with Windows 8 Proper (Metro UI).

Close...
It can use BOTH.... Wp7 framework runs as it does now and WinRT Apps run as they do on Metro.

There is no reason that both frameworks are NOT just offered, and there would be NO NEED for translation layer as .NET does not need translation...

Even something as advanced as a video model, video driver model, rendering model, and GPU threading added to a kernel and GPU virtualization technologies added to a kernel - that ALL occured with Vista and Windows 7. DID NOT require or NEED for Microsoft to remove the XPDM model from Vista or Windows 7, and this is because of the object nature of NT and extensibility that it can support both models transparently.

.NET is a much higher layer than WDDM and a much higher layer than even Win32, as it is not machine or architecture specific and its Apps are not any architecture binaries.

There is NO reason to not leave the WP7 framework in place and offer the WinRT Framework and if MFRs want to build an x86 phone, also run the full Windows 8 desktop version and offer the Win32 subsystem along side both. (Although it would a bit weird, there is nothing that prevents it from working.)

thenetavenger said,
There is NO reason to not leave the WP7 framework in place and offer the WinRT Framework and if MFRs want to build an x86 phone, also run the full Windows 8 desktop version and offer the Win32 subsystem along side both. (Although it would a bit weird, there is nothing that prevents it from working.)

Maintaining two different frameworks while making sure both have the same appearance is costly, both in time and money.

hmm....the resolution problem kind of reminds me of iPhone apps on iPad...I don't own an iPad (and this don't have complete knowledge of this situation, so don't take me as a reliable source of information ) but from what I've seen the way Apple gets iPhone apps to work on the larger iPad screen is they simply put a black border around the app until the app looks relatively nice. Now, I don't really see this working on the much smaller smartphone screens, but just wanted to point it out

Matthew_Thepc said,
hmm....the resolution problem kind of reminds me of iPhone apps on iPad...I don't own an iPad (and this don't have complete knowledge of this situation, so don't take me as a reliable source of information ) but from what I've seen the way Apple gets iPhone apps to work on the larger iPad screen is they simply put a black border around the app until the app looks relatively nice. Now, I don't really see this working on the much smaller smartphone screens, but just wanted to point it out

Android does a similar thing; allows you to run at the native resolution of the app (with black borders) or zoomed to fill the screen (at the lost of image quality due to it being stretched). It's fairly logical to assume MS will take a similar approach with WP8.

Matthew_Thepc said,
hmm....the resolution problem kind of reminds me of iPhone apps on iPad...I don't own an iPad (and this don't have complete knowledge of this situation, so don't take me as a reliable source of information ) but from what I've seen the way Apple gets iPhone apps to work on the larger iPad screen is they simply put a black border around the app until the app looks relatively nice. Now, I don't really see this working on the much smaller smartphone screens, but just wanted to point it out

Um, there would be some upscaling on higher resolution devices, but it is already inherent to both WinCE and WinNT video models. The nature of the WP7 platform though is Silverlight and resolution independent, unlike the framework that the iPhone and iPad use that try to bootstrap some 'scaling' and resolution independence after the higher resolution iPhone and iPad were scheduled to be delivered.

WP7 has some advantage here in the Silverlight OS platform model, and with the Windows CE and NT underpinnings, the video model and upper layers just fall into place. Windows scalability is underestimated or overlook in general, in the pathetic basic GDI system from Windows 3.0 was a fairly scalable application and UI drawing framework, and even that old version outclass what Apple offered on Macs until OS X was released, and XP and was catching up, and Vista and Win7 are a generation beyond OS X now again.
(Beyond just resolution as an example, displaying 48bit color is ONLY possible in Windows 7, OS X cannot produce anything over a 24bit color image, which is ironic that some graphic designers are buying new 30/32/36/40bit color displays, and hooking them up to OS X. This is something that Windows 7 'extends' just as it handles extremely high DPI displays that are beyond what current monitor can produce.)


This won't be the iPad issue, and WP7 developers may want to move their App to WinRT and Windows 8 DESKTOP, but for WP8, they don't have to do anything, and their Apps will run and scale automatically...

Think of it this way.

If you want your unmodified WP7 app to run on Windows 8 Metro, there is a bit of boostrapping code that needs to change.

If you want your W8 app to run on WP8, no problem.

Now, if you want your WP7.5 app to run on WP8 (unmodified) it will because Microsoft will provide the shim between Silverlight/XNA and WinRT.

For optimum performance and to take advantage of new features, re-code and recompile.

dotf said,
Think of it this way.

If you want your unmodified WP7 app to run on Windows 8 Metro, there is a bit of boostrapping code that needs to change.

If you want your W8 app to run on WP8, no problem.

Now, if you want your WP7.5 app to run on WP8 (unmodified) it will because Microsoft will provide the shim between Silverlight/XNA and WinRT.

For optimum performance and to take advantage of new features, re-code and recompile.

There is a shift in retooling a WP7 Apps for Windows 8. However, there is NOTHING required for Windows PHONE 8, as it will be using a newer version of the SAME .NET/Silverlight OS Platform framework for running Apps, that Windows 8 DESKTOP does not use, as it encourages the Apps to use tablet and desktop features like higher resolutions screens, etc...

This is NOT about WP7 to Windows 8, this is about WP7 to WP8, which will require NO retooling/revisiting by WP7 developers, as Microsoft and stated MANY times in interviews and developer conferences and even in whitepapers and documentation.

If you want to move a WP7 App to Windows 8 Desktop/Server/XBox, you are going to have to make a few change probably, as you need to check for a an accelerometer, SMS support, and Phone specific features, as well as adjust and create new resolutions and integrate with Metro on WinRT in new ways, as it DOES more than the WP7 platform currently offers. You know, there are things you need to check to see if a computer has, that is assumed and mandatory for a WP7 to have...

thenetavenger said,

...

They seem to be under the impression that the rumours of Microsoft replacing the Silverlight based runtime with a WinRT style replacement (which, depending on what their roadmap for desktop Silverlight turns out to be, may just very well be the case). Although, either way, there's nothing stopping them including both frameworks in the next version of Windows Phone and maintaining compatibility.

jasonon said,
no ****? if they didn't continue the app compatibility forward it would kill the platform

And here's the great thing about this update model, they can phase out old OS iterations faster than other approaches.
Just get all devices on the new kernel and gracefully retire launch software.

Well considering I've heard all WP7 devices will be upgradable to WP8 (Apollo) I would of thought cross compatibility would be a dead cert to be honest (otherwise they'd end up with alot of angry customers forced to rebuy their apps or find alternatives that work).

I have to admit this is what really impresses me about Windows Phone, not only are MS committed to making it the best mobile OS out there but all devices are getting updated to the next major version, something Android keeps failing to do (I'm an Android fan too). If it wasn't for the fact I cannot stand the Metro UI, I'd get a WP7 device for sure. MS did a good job but just not my cup of tea, I just hope Google pays close attention to what MS are doing and takes away some ideas on how to improve Android [alot].

They have stated this again and again since they debuted the WP7 Silverlight/.NET OS Framework, and is why they built the OS platform using .NET. They specifically said that developers would NOT have to revisit Apps for future portability to newer versions, which means Apps shouldn't have to be touched by developers.

How has THIS NOT BEEN CLEAR? Is it the public or the horrid lack of IT journalism/understanding reporting on this stuff?

A WinCE kernel, a WinNT kernel, it doesn't matter, the Apps run in the OS platform layer, they don't care what is underneath them. This was designed around .NET which offers ultimate portability that puts other similar attempts like JAVA to shame.

With WinCE and WinNT combined with an upper layer OS framework using .NET it is the most adaptable and portable 'model' that OS Theory offers.

(The kernel uses a strong portable model that is coded to a uniform architecture that is supplied by an agnostic HAL, this lets the base OS kernel simply run on any architecture no matter how use registers or allocate memory or any other variances in architectures and CPUs, with a HIGH level of performance, that Linux does NOT offer.)

The .NET Framework used as the upper layer Application/OS platform provides a compiled App base that has no machine code and doesn't care about how the OS platform is giving it memory let alone how the kernel is handling low level architecture operations.

This is why this works so well, and in ways that JAVA failed as an Application layer portable framework and why portable OS code models that rely on C as the 'portability' factor cannot easily move to new architectures without recoding the 'C' code to the architecture EVERY time, like Linux does.

Microsoft has not only made this clear enough that a non IT person should understand, but the fact that a developer or anyone that deals with technology should be slapped for not understanding.

Win32 ran on a monolithic Win9x kernel, and yets runs on the Win32 subsystem on top of WinNT today, and people don't realize that this was because of the brilliance of the NT design model, and was SO freaking seamless that most consumers didn't realize XP was a different OS than Win95. (To the point they still tried to make fun of XP for Win9x's kernel's shortcomings, security issues, crashes, registry issues, FS issues, etc... That today people still reference when trolling Windows, and hasn't applied to Windows since WinME was killed off.)

Wow... Just freaking wow...

In other news, the Earth revolves around the Sun, and water is wet....

thenetavenger said,
In other news, the Earth revolves around the Sun, and water is wet....

I thought it was that obvious too, but some people out there want to spread seeds of doubt. Most likely the original tweet was from some phandroid.

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