Last May, when a new version of the embedded operating system Windows CE was announced by Microsoft at an embedded systems conference in Las Vegas, the company indicated that a larger percentage of its source code would be available for licensed sharing than for Windows CE 5.0, for which 56% of its source code could be licensed.

The questions on developers' minds were, does this mean Microsoft will license the file system code, and how much of the embedded OS will still be under wraps?

This morning, during the company's "virtual launch" event, developers got answers to both: Yes to the file system, and zero percent kept secret. As a Microsoft spokesperson confirmed to BetaNews this afternoon, the company will now be licensing the entire source code of the new version of what's now called Windows Embedded CE to purchasers of Windows Embedded CE 6.0 for development into a platform.

Unlike a conventional Windows, Embedded CE is a kind of core system around which a "platform" -- a branded operating environment for small devices -- is developed. Under the company's new licensing scheme, when a company purchases Embedded CE 6.0, it gets Visual Studio 2005 Professional Edition, BetaNews was told this afternoon.

Along with that development environment will be Platform Builder, whose name may be changed to Windows Embedded CE Toolkit, and which was previously only available from Microsoft as a separate download.

The 100% sharing campaign may actually come as a surprise to Microsoft's own support staff, which this morning released instructions regarding how to tell whether a portion of CE 6.0 is shared or not. With today's news, which BetaNews confirmed, there is no "not."

However, not all of Embedded CE's source code will be licensed for free. A significant portion of it will be free to those who have already purchased and licensed Embedded CE "in the box." The remainder of the code will be licensed under Microsoft's existing "Premium Shared Source Program" terms, specifically to "qualified OEMs and partners."

As the spokesperson told us today, although the fees have not yet been disclosed, Microsoft will consider this program a legitimate source of revenue.

The fact that at least those who can afford it can see everything that Microsoft put into Windows Embedded CE 6.0, will be of interest to those who responded to the news of its impending release last May with questions about its relative interoperability, especially in the face of rising competition from Linux and embedded UNIX. Operating systems based on industry standards, some have argued, are more prone to being shared under open-source licenses, which lends greatly to their inherent interoperability.

To subscribe to that argument, though, one must concede that support for industry standards, including those as ordinary as SNMP, must necessarily lend themselves to Linux, as if operating systems and stacks were the same thing. If a company can conceivably develop a proprietary platform around the Windows Embedded CE core, and then distribute that platform -- including Microsoft's proprietary elements -- without fear of being picked on by Microsoft's legal department, the whole issue of Linux being embraced by the rest of the world might not matter.

"The Shared Source program provides full source-code access for modification and redistribution by device-makers (subject to the terms of a license agreement)," reads Microsoft's statement today, "who are under no obligation to share their final designs with Microsoft or others. Although the Windows operating system is a general-purpose computing platform designed for creating a consistent experience, Windows Embedded CE 6.0 is a tool kit device-makers use for building customized operating system images for a variety of non-desktop devices."

Today, Microsoft released its 180-day limited use trial edition of Windows Embedded CE 6.0 for free evaluation.