July 18–With Microsoft Corp.’s reorganization last week, a curious thing has now happened at the three companies that are the biggest players in the world of operating systems.

In the last year, Apple Inc., Google Inc. and Microsoft have all moved to put one person in charge of both their mobile and desktop operating systems.

Coincidence? Perhaps. But Colin Gillis, an analyst at BGC Partners, who mentioned the trend in a recent conversation, says the shift seems to be pointing each company toward convergence some time, even if that point remains far down the road.

“Do these companies want both of those operating systems?” Gillis said. “Probably not.”

Over time, Gillis said, as mobile hardware becomes more robust, these companies can build more features into their mobile OS. At the same time, users of desktops and laptops are growing to expect some of the mobile features on those platforms.

“In the first round of phones, you need a lighter operating system,” Gillis said. “But now, we want convergence.”

Apple took the first step in this reorg trend late last year when it appointed Craig Federighi to be senior vice president of software engineering. That put him in charge of iOS and Mac OS.

Although still separate, the two OS platforms have been inching toward each other over time. Apple, for instance, created an App Store of the Mac OS. And more recently, with the coming debut of iOS 7, desktop users will be able to use features such as the iBookstore that were previously available only on the iPhone and iPad.

Google took the next step in this direction in March, when it named Sundar Pichai, who had been in charge of the Chrome OS, to be senior vice president of Android, Chrome & Apps. The immediate reaction from the blogosphere was that this was a clear signal that Android and Chrome would be merged. TechCrunch wrote that it “signals the clear unification of Android, Chrome & Apps.”

But Pichai later said that Chrome and Android would remain separate.

“I don’t think my views have changed much. Android and Chrome are both large, open platforms, growing very fast,” Pichai told Wired Magazine in May. “I think that they will play a strong role, not merely exist. I see this as part of friendly innovation and choice for both users and developers.”

Microsoft completed the trifecta this month with its big reorganization, which made Terry Myerson executive vice president of the Operating Systems group.

Although Microsoft was the last of the three to make this move, it had been the most aggressive in terms of talking about creating one OS for all platforms.

Windows 8 was supposed to be the beginning of that merging of desktop and mobile. And indeed, the launch of Windows 8 has pushed a number of partners to move toward introducing laptops and desktops with touch screens this year.

But longtime users seem to have said it’s too far, too fast.

And so Microsoft is backing down a bit, promising that Windows 8.1 will enable users to boot directly to the traditional desktop. The company hopes that will allow customers to gradually evolve toward the mobile, touch-screen world.

That, in fact, seems to be the pace Google, Apple and Microsoft are taking toward merging their desktop and mobile OS experiences. It will be evolution, not revolution.

That said, the companies have all made clear statements that they want folks in their respective OS groups to be working much more closely together. And in a rare bit of agreement, all three companies have basically come to the same conclusion at about the same time.