Mobile device hackers this weekend began sharing what they claim is the final, shipping version of Windows Phone 7.5, the next version of Microsoft's smartphone OS. However, even if this build is indeed the RTM ("release to manufacturing") build of Windows Phone 7.5—and there is evidence to suggest otherwise—it's still not really the completed, final version of the OS, since it lacks the device- and platform-specific adaptations that will eventually be provided by the software giant's partners.

The software in question is identified as build 7.10.7720.68, or simply build 7720. And yes, in a classic confusing move only Microsoft seems capable of making, the version number of Windows Phone 7.5 is indeed 7.1, and not the more logical 7.5.

This build is clearly very close to final at the least. The near-final release candidate (RC) version of Windows Phone 7.5 that Microsoft previously gave out to reviewers and testers was build 7712. There are no reportedly new features in the build, which makes sense given Microsoft's previous statements about the RC being "feature complete."

Microsoft announced that it had released Windows Phone 7.5 to manufacturing on July 26, more than a month earlier than I had expected. But this early release was later explained by the fact that it wasn't truly done then because Microsoft's partners still needed to add code to the release. It's unclear when that process will be finalized.

This unofficial, possibly RTM release is not recommended for typical users for many reasons, not the least of which is its dubious origins. But the updating procedure is also lengthy, monotonous, and prone to failure; in fact, it could possibly "brick" your phone. Some report that updating to build 7720 takes as long as two hours to complete.

I looked at the build briefly Saturday morning but decided to ignore it for these and many other reasons. But those with sturdier constitutions and looser morals can find the build and an incredibly dense, multi-step updating process on the XDA Developers website.

I'll be reviewing Windows Phone 7.5, which was previously code-named Mango, in the coming weeks. In the meantime, check out my hands-on look at the Mango release candidate and a previous, more exhaustive Mango overview, both of which are available on the SuperSite for Windows.