Microsoft has released Windows 8.1 to manufacturers, but developers will have to wait until it's in the hands of consumers before they get to test their apps against the final code.
Microsoft generally lets TechNet and MSDN subscribers download operating system releases as soon as they hit the "release to manufacturing" (RTM) milestone, so that partners and developers can get a head start on testing the OS with apps and hardware.
However, Microsoft has confirmed that this time developers won't get their hands on the finished code until consumers do – on 18 October.
Microsoft has given no reason for withholding the code from developers, although a blog post from Microsoft's corporate vice president, Antoine Leblonde, seems to suggest the OS isn't actually finished yet.
"In the past, the release-to-manufacturing (RTM) milestone traditionally meant that the software was ready for broader customer use," he writes.
"However, it’s clear that times have changed, with shifts to greater mobility and touch as well as the blurring of work and personal lives. As such, we’ve had to evolve the way we develop and the time in which we deliver to meet customers with the experience they need, want and expect. We’ve had to work closer to our hardware partners than ever before.
"While our partners are preparing these exciting new devices we will continue to work closely with them as we put the finishing touches on Windows 8.1 to ensure a quality experience at general availability on 18 October," he added.
"This is the date when Windows 8.1 will be broadly available for commercial customers with or without volume licensing agreements, our broad partner ecosystem [and] subscribers to MSDN and TechNet, as well as consumers."
Developers in the cold
The delay means there is unlikely to be many – if any – apps that take advantage of the new APIs for Windows Store apps on release day.
Although Microsoft released a public preview of Windows 8.1 at its Build conference in June, developers will want to test against the final code before releasing apps on to the Windows Store.
The decision has infuriated developers. "How are we supposed to test our software for Windows 8.1?" writes IzsakSVK, commenting on Leblond's blog post. "The day it will be automatically installed on users' machines? So we - software developers - can take blame that applications don't work on Windows 8.1? Great way to lose your partners."
Another, identified as Bav0, writes: "We pay thousands for MSDN access so we can test our software/apps properly... before GA, [it] is an important part of that process!
"We don't care about a couple of bugs in your OS, we [care] about bug[s] in our software. Most of us actually want to support Windows 8.1, a lot of us want to get apps ready for the awesome 8.1 features, but we can't properly do that unless we get the RTM bits before the public gets the Windows 8.1 update!"