That would be roughly akin to CocaCola (COKE) posting its top-secret formula online. Crazy, right?

Maybe not, although the very notion would have been unthinkable not too long ago. But it is now on the table considering all the things Microsoft (MSFT) has done over the past few years to embrace the open-source community.

The most recent example is last week’s news that the company is open-sourcing its PowerShell tool that helps developers manage Windows applications. Two years ago, it open-sourced the core elements of its .Net framework which is basic building blocks for software developers. This GitHub site lists all Microsoft’s open-source projects.

Generally speaking, in the open-source world, the basic nuts and bolts (aka the source code) of the software is available to developers who want to see it or even tweak and customize it, provided they comply with the software’s license. That is something they definitely cannot do now with Windows or Office, Microsoft’s other huge money maker.

Open-source software is usually free or close to it, although users may pay for support, maintenance, and advanced features. Proprietary software vendors, on the other hand, charge what the market will bear for the software upfront and then often tack on a percentage of that price for continued updates and support.

That’s the model that built lucrative software businesses at Microsoft, Oracle (ORCL), SAP (SAP) and other software giants. It’s also been under siege for more than a decade as the development world has shifted to open source technologies that underlie most of the world’s modern cloud computing systems.

Open source proponents say mounting evidence, including the fact that the Windows desktop operating system accounts for a dwindling piece of the Microsoft’s overall revenue may make an open-source decision more palatable for Microsoft (MSFT).

“It seems like the monetization model has shifted,” said Donnie Berkholz, research director at 451 Research.

Basically, Microsoft can charge for value-added hosted services running on its Azure cloud computing offerings that compete with Amazon (AMZN)Web Services. That even Microsoft acknowledges eroding operating system prices is borne out by the fact that it made free upgrades to its year-old Windows 10 until last month and has offered earlier versions of the operating system for free on small tablet devices.

Still, having said that, Berkholz cautioned that Microsoft still makes a lot of money on Windows, including on the Windows Server operating system, so this would still be a tough call.

A bigger problem with any software that has been around this long and that is run on so many types of hardware is that it will include code supplied by third-party companies that supply components like graphic processing units (GPUs) and other hardware that has to interact with the operating system. The ownership of all that code would have to be sorted out.

“There may be covenants and patents in there that would make open sourcing Windows difficult,” noted Bryan Cantrill, chief technology officer of Joyent. Generally, he doesn’t see much point in open sourcing Windows per se, but would love to see Microsoft open up other parts of its product stable, including its tools for debugging software to the open-source community.

Several open source proponents welcome the notion of a free-and-open Windows.

Saïd Ziouani, founder and chief executive of Anchore and a former executive at Red Hat (RHT), said the notion of opening up Windows and the wealth of experience associated with it over the past 30 years, would be a boon both to Windows and open-source developers. “Think of bringing that incredibly rich ecosystem of Windows developers into the open source world,” he told Fortune.

One key benefit of such a move, in theory, would be this code would be scrutinized by many more developers than in the past, and that could lead better security and fewer bugs.

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Another benefit to Microsoft is that it would help it recruit the best and brightest software development talent. Many engineers and developers graduating from college have been eager to work in the open source arena.

Open-source aficionados point to Microsoft’s recruitment of Wim Coekaerts, Oracle’s top Linux guy, in April as another sign that all bets are off. Infusion of new talent and Microsoft chief executive officer Satya Nadella’s stated determination to make Microsoft welcoming to open-source ideas, as a key foundational change.

In November, after years of wrangling, Microsoft and Red Hat finally agreed to work together to support Red Hat Enterprise Linux and Windows that run in the same shops, another sign of acceptance of the now 25-year old open-source operating system that has competed well with Windows Server for data center supremacy.

Given all that’s happened in the interim, it’s interesting to look back at what Azure chief technology officer Mark Russinovich said last year during a panel at the Chefcon tech conference. As described in this Wired report he was asked point-blank whether Microsoft might open source Windows. Russinovich, definitely on the hot seat, left the door open to all options.

“It’s definitely possible. It’s a new Microsoft. Literally every new conversation you could imagine … has happened,” he noted.

He also pointed out the pitfalls that ranged from “getting rid of profanities” in the code—yes, developers have been known to curse in their their code—to sorting out the legal and intellectual property issues mentioned previously. All of that is doable, at a price. The issue is whether the price outweighs possible benefits.

Russinovich also seemed to imply that because Windows is a big, venerable, hunk of software code written over many years, any decision to open source it would be harder.

“You can open-source something that may come with a build system that takes rocket scientists three months to set up and then what’s the point?” he said.

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IDC analyst Al Gillen and others were skeptical that anything will really happen here. Sure, Microsoft has done some open-source things above and beyond what has already been mentioned. It is, for example, porting its popular SQL Server database to Linux. This means you can buy SQL Server and have a non-Windows Server alternative operating system to run it on. But that is not the same as open sourcing it.

Perhaps the biggest hurdle is that while the Windows code base is humongous, the number of people with deep knowledge of its internal workings is not big at all.

“It would take years before any community could form and actually deliver some useful input to Microsoft that would help with that code,” Gillen said.

A former Microsoft executive who requested anonymity agreed. “I am hard pressed to see how this would drive any material beneficial outcome for Microsoft,” he noted. “You need more than ‘hell freezes over’ headlines.”

Yet, as Amrith Kumar, chief technology officer for Tesora, a maker of an open-source database service, said he thinks an open-source Windows is definitely an option for Microsoft. Will that happen soon? Not necessarily but: “I certainly think that, taken in the context of the changes Microsoft has made over the past few years, this seems a perfectly possible thing and one that wouldn’t surprise me.”

And, as we keep hearing, everything is on the table at Microsoft these days, so maybe we’re getting closer to that chilly day in hell.