With the Internet increasingly taking on the role of the PC operating system and the growing prevalence of virtualization technologies, there will be a day when the Microsoft Windows client OS as it's been developed for the past 20-odd years becomes obsolete.

Microsoft seems to be preparing for that day with an incubation project code-named Midori, which seeks to create a componentized, non-Windows OS that will take advantage of technologies not available when Windows first was conceived, according to published reports.

Although Microsoft won't comment publicly on what Midori is, the company has confirmed that it exists.

Several reports - the most comprehensive to date published on Tuesday by Software Development Times - have gone much further than that.

The report paints Midori as an Internet-centric OS, based on the idea of connected systems, that largely eliminates the dependencies between local applications and the hardware they run on that exist with a typical OS today. It claims Midori is an offshoot of Microsoft Research's Singularity OS, which creates "software-isolated processes" to reduce the dependencies between individual applications, and between the applications and the OS itself.

With the ability today to run an OS, applications - and even an entire PC desktop of applications - in a virtual container using a hypervisor, the need to have the OS and applications installed natively on a PC is becoming less and less, said Brian Madden, an independent technology analyst. "Why do you need it?" he said. "Now we have hypervisors everywhere."

Madden suggested that a future OS could actually be a hypervisor itself, with virtual containers of applications running on top of it that can be transferred easily to other devices because they don't have client-side dependencies to each other.

And while he has no information about Midori beyond the published reports, he said descriptions of it as an Internet-centric system that provides an overall "connectedness" between applications and devices makes sense for the future of cloud computing and on-demand services. Microsoft likely recognizes the need for this even if the actual technology is still five or more years out, Madden said. "They're preparing for the day when people realize we don't need Windows anymore" and thinking about what they will do to remain relevant, he said.

Indeed, Microsoft has been emphasizing its virtualization strategy, based on its new Hyper-V hypervisor, beyond merely virtualizing the server OS. The company also is moving full steam ahead with plans to virtualize applications and the desktop OS as well.

Using virtualization in these scenarios would eliminate the problems with application compatibility that are still giving headaches to Vista users, and that have made the OS a liability rather than a boon for some Windows power users and enterprise customers.

If Midori is close to what people think it is, it will represent a "major paradigm shift" for Windows users and be no easy task for Microsoft to pull off, said Andrew Brust, chief of new technology for the consulting firm Twentysix New York.

He said challenges to an OS like Midori would be both technological complexities and the "sobering compromises" that must be made when a product moves from being a research project into commercialization. "I would expect those in abundance with something of this scope and import," Brust said.

Though he has not been briefed by Microsoft on Midori, Brust said the idea makes sense because Microsoft needs to drastically update Windows to stay current with new business models and computing paradigms that exist today -- particularly to help the company compete against Google on the web.

"Breaking with the legacy of a product that first shipped 23 years ago seems wholly necessary in terms of keeping the product manageable and in sync with computing's state of the art," Brust said. "If Midori isn't real, then I imagine something of this nature still must be in the works. It's absolutely as necessary, if not more so, to Microsoft's survival as their initiatives around Internet advertising, search and cloud computing offerings."