Microsoft's Windows 10 will not have a fragmentation problem, analysts argued, even though its rapid development tempo and a host of update cadences will spin off so many versions that not everyone will be running the same code, or even have the same features, at any one time.
"There will undoubtedly be some fragmentation of the installed base due to timing but it shouldn't be extreme, and indeed should be better than the situation today," contended Steven Kleynhans of Gartner.
For Kleynhans and others, Windows 10 will ultimately be an improvement over the current situation, where the majority are on Windows 7, but sizable numbers remain on other editions, notably 2012's Windows 8 and 2013's follow-on, Windows 8.1, and 2001's Windows XP, each of which is significantly different.
Still, Windows 10 will not exactly be the monolithic operating system that Microsoft has portrayed: The same code running on a billion systems.
Because Microsoft will be constant tweaking, refreshing and upgrading the OS, it will be a moving target compared to past editions, which once finished were generally left alone, serviced by security patches and behind-the-scenes bug fixes, but not significantly altered.
The Redmond, Wash. company experimented with a different model with Windows 8.1, which shipped a year after its Windows 8 parent with new features and functionality, and some limited user interface (UI) and user experience (UX) modifications. That practice has been both greatly expanded and accelerated with Windows 10, which will receive updates about three times a year.
But the churn of Windows 10 changes isn't the only new practice in play: The multiple release tracks Microsoft is to offer will result in some users running Build n, while other run n-1 and still others n-2 (where n is the most current). Those tracks -- Microsoft calls them "branches" -- will offer customers a range of update and upgrade tempos, from the previews handed to Windows Insider participants to the automatic get-everything Current Branch (CB) for consumers to the Current Branch for Business (CBB), which allows for delayed deployments.
The multiple tracks will create several "forks" in Windows 10 once the operating system starts to deliver the three-times-a-year updates and upgrades. By Computerworld's count, which was based on Microsoft's description of the process earlier this year, in October 2016 there will be three builds active simultaneously: The original Build 1 released in December 2015 (still being run by those on the CBB track who have postponed the update using Windows Server Update Services, or WSUS), April 2016's Build 2 (still allowed via CBB served by Windows Update for Business, or WUB), and Build 3, issued in August 2016 (consumers on the CB track).
Any given build, say No. 1, can be in use somewhere over a 16-month stretch.
And that doesn't even count Windows Insiders, who will presumably be on some kind of preview of Build 4 as it works its way to a December 2016 release to CB. "Insider is only beta testing and not for production," noted Gary Chen of IDC, essentially discounting the preview program from the forks discussion because of its limited appeal.
According to Microsoft, some five million users are now running Insider -- a paltry number compared to the 1.5 billion running some form of Windows -- but data from metrics firm Net Applications indicates that the number is half that, about 2.6 million.
Where Insider rings fit in
Complicating matters are the "rings" that Microsoft has used in the Insider program, and will replicate in the other branches. Through the months-long Insider, Microsoft has offered testers a "slow" ring and a "fast" ring, with the latter pushing updates more frequently, the former less often but with more stable code.
Microsoft has said that the CBB branch, and by implication the CB branch as well, will have rings of their own -- perhaps the same fast and slow of Insider -- so users have some choice about when they receive updates and upgrades. In May, OS head honcho Terry Myerson said, "There will be new rings specifically for enterprises, for businesses that want to be in slower rings to make sure all the kinks are worked out in any updates before it gets applied to their system."
Adding rings to the branches, assuming two rings per, doubles the number of different versions active at any one time.
Meanwhile, large organizations and corporations with volume licensing and Software Assurance agreements for the Windows Enterprise edition will assign significant numbers of systems to the Long-term Servicing Branch (LTSB), a static channel that will resemble the historical practice of letting the code be, updating only for vulnerability patches and critical repairs. A LTSB build can be run, Microsoft has said, for as long as 10 years, but interim builds will be issued to refresh that branch every two or three years.
The upshot is that there will be a lot of different flavors of Windows 10 out and about concurrently.
"We've at least got five rings ... the 'ring count,' if you will," said Wes Miller of Directions on Microsoft, ticking off the Insider fast, Insider slow, CB, CBB and LTSB. "So that's at least five milestones to track. Then you've got different states of each: Customer has applied the latest patches or hasn't applied the latest patches. So that's at least 10."
How different the forks will be is unknown -- Microsoft may not know itself at this point -- but the fragmentation could be of concern to developers and support teams, with each group unsure how many Windows 10 users are on a specific branch and even ring at any given moment, and thus hesitant about supporting a moving target, or uncertain about questions or problems that may pertain only to one ring or branch, but not later releases.
Historically, Windows has had both the reality and the appearance of similar forks, what with the various editions -- Windows Vista, Windows 7, Windows 8.1 -- and subsets within those editions, like Windows 7 Service Pack 1 (SP1) and Windows 8.1 Update. But with the exception of Windows 8 versus Windows 8.1, internally the differences have been on a patch and bug-fix level, not on a feature, UI or even API (application programming interface) level, as Windows 10 promises.
But analysts downplayed any problem that the plethora of Windows 10 releases may present.
"There are likely to be at least six" rings, said Chen. "A fast and a slow for each of Insider, CB, and CBB. But I don't believe this will cause fragmentation in Windows beyond what exists today. With the classic Windows releases, you could still have people on different versions, such as service packs or point releases like 8/8.1.
"There's really only four rings that matter, CB and CBB, and a business may only be concerned about CBB, so that's effectively two rings to manage, not a big change from what they support today," Chen added.
Frank Gillett of Forrester Research agreed. "It won't be nearly as bad as a decades-long trail of multiple Windows versions or the crazy variety of Android forks in the world," he said.
No Android problems, most foresee
Android has been the poster child of fragmentation, not because of its release tempo -- Google issues major new editions annually, on the same pace as Apple does iOS -- but because carriers update existing handsets very slowly or not at all. Android versions 4.1 through 4.3, aka "Jelly Bean," which were released between July 2012 and July 2013, currently account for 38% of all editions, while October 2013's Android 4.4 (KitKat) powers 39%, and the newest, November 2014's Android 5.0 and March 2015's 5.1 (Lollipop), have a combined 12% share.
(On the other hand, September 2014's iOS 8 powers 84% of all of Apple's mobile devices, with just 14% running 2013's iOS 7.)
"This will not happen to Windows. Android fragmentation is a very different problem," said Chen. "There you have OEMs customizing and developing Android that they get from Google upstream for their devices, and they control the development and release downstream. Windows on PC does not follow the mobile model. Every Windows machine gets largely the same Windows direct from Microsoft, any OEM customizations are only on the surface, and all the updates are controlled by Microsoft."
The amount of time that a specific build will be active was also important to the analysts' argument that Windows 10 would not be as fragmented as Android, or for that matter, Windows as it is today.
"Fragmentation should be limited to 18 months or so, with the exception of LTSB, certainly not reaching back several years as it often does today," said Gartner's Kleynhans.
But not everyone was sanguine about the multiple branches, rings and builds. Miller of Directions on Microsoft has qualms.
"Consumer developers will probably be able to play the 'we don't worry about Windows Insider builds' card, and focus primarily on CB and CBB builds," Miller said. But "how IT organizations and developers will test and ensure their own quality across a range of OS releases like this has been one of my key concerns since I first caught wind of Microsoft's plans."
Kleynhans also had misgivings, although his were about the mechanics of the process.
"How will [Microsoft] identify each update?" Kleynhans asked. "We know that the OS will be called Windows 10 regardless of what updates have been delivered and installed. But as for identifying the state after each update, we don't know if Microsoft will stick with the build number, opt for a simplified numbering scheme, go back to point identifiers -- Window 10 v 10.1, 10.2 ... similar to what Apple does with OS X -- or maybe use something more date oriented, like Windows 10, July 2016. There will have to be something to help developers understand what they are facing in the field."