Although there are many ways in which one might measure the relative success of competing platforms, developer interest has got to be near the top of the list. And if a recent IDC report is to be believed, Microsoft has a lot of work to do to make its most recent platforms -- Windows 8 and Windows Phone 8 -- successful. In fact, IDC is describing next year as a “year of reckoning” for the would-be devices and services company.

“Mobile platforms that fail to crack the 50 percent barrier of developers that are ‘very interested’ in developing apps for them will be on a gradual track to demise,” the IDC report claims. And where does Microsoft now fall on this scale? Thirty-three percent. (Don’t feel too bad, though: RIM’s at just 9 percent.)

I’ve argued in the past that Windows 8 -- at least its Metro part -- is a brand-new mobile platform and that Microsoft’s strategy for moving its 1.3 billion strong user base forward was to meld that new platform with the established Windows desktop. This strategy, though controversial, is the reason Microsoft refers to Windows 8 as a “no compromises” OS, because it can ostensibly be used as well on the traditional PCs of the past as it can on the mobile devices of the present and future. (Opinions vary, but that’s the theory.)

Regardless of your take on Windows 8, targeting the mobile world makes sense. IDC says that sales of mobile devices will grow by 20 percent next year and generate 57 percent of all IT market growth; excluding these devices, the IT industry's growth will be just 2.9 percent. More to the point, mobile devices are “the new primary design point for end-user access,” IDC notes, not PCs. So winning the battle for developers is key to succeeding moving forward.

The trouble is, there’s been a lot of bad news about Windows 8 lately. I’ve reported several times about Microsoft’s internal beef with PC makers, which it believes sabotaged the Windows 8 launch by not delivering the promised next-generation devices to market in a timely enough or voluminous-enough manner. And NPD said late last week that first-month sales of Windows 8 PCs and devices were terrible, down 21 percent over the same period a year earlier.

Microsoft cheerleaders -- yes, they’re out there -- will argue that it’s too early to weigh in on Windows 8 sales. And while I’d remind them that Microsoft has already done so internally, nicely killing that theory, let’s just pretend that everyone’s a winner and move on: Surely, there must be some way to determine whether Microsoft’s nascent mobile platforms are poised for success or irrelevance.

That’s where the IDC report comes in.

According to IDC, which surveyed almost 5,000 developers, Windows 8 and Windows Phone are in a lot of trouble. While iOS (iPhone, iPad), Android (handsets and tablets), and HTML5/mobile web fall well above that crucial 50 percent mark, Windows 8 and Windows Phone fall well short. Only 33 percent of developers said they were very interested in writing Windows 8 “Metro” apps. And only 21 percent were interested in doing so for Windows Phone.

(Fully 85 percent of responders were very interested in writing iPhone apps, and 83 percent were very interested in writing iPad apps. Android handsets and tablets came in at 76 percent and 66 percent, respectively, whereas HTML5/mobile web was at 66 percent as well.)

Redmond, we have a problem.

What really worries me here is that developer outreach is the one area -- possibly the only area -- in which Microsoft is already doing a fantastic job with both Windows 8 and Windows Phone. Its tools, based on Visual Studio, are without peer. The development APIs, called Windows Runtime (WinRT) for Windows 8 and Windows Phone Runtime (WinPRT) for Windows Phone, are new, sure, but clean, understandable, and straightforward, and an easy leap from the .NET past. The documentation is excellent -- less so for Windows 8, but it’s getting there -- and Microsoft is building an ever-growing collection of superb training materials, including some excellent video series. (Check out Microsoft Virtual Academy for just a small subset.) I’m really not sure how much more they could do.

This much is certain: If Microsoft wants to avoid a Vista-style debacle, it needs to reach out to all of the groups that matter -- not just consumers and business users, but also developers -- and do the one thing it never did during this system’s insular development schedule: Listen to feedback and work aggressively to implement it. Window 8 is a solid foundation for PCs, tablets, and phones. But it needs some love, and some help, fast.