Yes, Microsoft is pursuing a different type of operating system, which goes by the name of Midori. And, no, it's not the next version of Windows.
The Midori subject has gotten a great deal of attention in recent days, with the fires only fanned by the fact that Microsoft has refused to say anything about Midori beyond confirming that it is an "incubation project" within the company. ZDNet's Mary Jo Foley noted its existence in her Microsoft 2.0 book, while more recently SDTimes posted a bunch of details on Midori based on internal documents.
From there, there has been plenty of speculation about what Midori is and isn't.
Here's what I've been able to confirm:
Midori is related to Singularity, aand is basically a look at how one might architect an operating system from the ground up, given what we know now about computing and where things are headed in terms of parallelism and cloud computing. Longtime Microsoft engineer Eric Rudder is the one leading up the Midori effort.
Whereas Singularity was a research effort firmly confined to a small team of researchers inside Microsoft's in-house labs, Midori is an effort to see if there is something commercially viable that could come out of it, though it could be years off and come in pieces if it comes at all.
The one public mention I found to Midori was within a research paper on a bug-finding program called Chess. On one PowerPoint slide, it mentions a list of "current Chess applications" of which one bullet point is "Singularity/Midori (OS in managed code)."
That syncs with the SDTimes report, which talks about Midori as an OS for the age in which computing resources can be either local or in the Internet cloud and in which processing tasks can be split among multiple processors and multiple machines.
It's worth noting that Microsoft often has incubation projects that seek to explore whether an all-new approach to a product might be justified. That said, up to this point, every update to Office and Windows has been some type of incremental improvement, not a ground-up rewrite.
Back in 2000, the company had an effort called NetDocs that many thought might replace Office with an online productivity suite. Eight years--and at least three Office versions later--people are still wondering when we will see such a product from Redmond.
That suggests to me that the arrival of Midori or some similar approach as a Windows successor is something that is a long way off, if it ever happens.
Microsoft has struggled to change even single subsystems of the Windows operating system, such as the file system. Microsoft has had both Cairo and WinFS projects, ultimately opting instead to stick with trying to build on top of what is already there.
The fact, though, that Microsoft is thinking about new ways it might do an operating system should not come as a surprise. I'd be surprised if they weren't exploring that idea.
What will be more interesting is if Microsoft actually does release something all-new. With its much smaller and mostly consumer base, Apple has shown several times a willingness to sacrifice compatibility in order to take the Mac in a new direction--most notably the shifts from 68000 processors to PowerPC, from OS 9 to OS X and from PowerPC to Intel chips. Microsoft, though, with its huge base of business and consumer users, has long favored compatibility over new capabilities and approaches.
The question is how long this approach can continue. I (and others) have been asking for some time whether Windows hasn't gotten too difficult to update. Take Longhorn/Vista. After a few years of work, Microsoft decided the major architectural changes it was planning were too drastic. It went back to the drawing board, but even the more modest changes it made with Vista have come under attack.
I wonder if, in this day and age, it wouldn't be possible for Microsoft to emulate all of Windows, while moving forward with a more modern software approach, sort of like Apple did with the "classic" mode in OS X. I have no idea if that's anywhere in the cards or not.
But if anyone wants to share some more Midori--I'm up for another round.