Windows 8 unidentified May 2011 build

On 29 May 2011, four days before Windows 8 was unveiled to the general public at All Things Digital (D9) and in the lead-up to the public release of the Windows Developer Preview, an internal Microsoft video was recorded which showed off an unknown shell branch build, which featured significant UI changes that would eventually be reverse-integrated into mainline Windows branches during the course of several months between May and August.

The video demonstrating the build in question was publicly released on 16 October 2022 in issue 102 of former Windows division president Steven Sinofsky's account of events during their time at Microsoft, titled Hardcore Software, 11 years and 4 months after the footage was recorded.

Observations
As previously mentioned, various user interface changes observed in this build would eventually be merged into mainline Windows branches from May through August 2011.

A newer variation of the Windows Aero visual style is used in this build, coupled with the updated Segoe UI font (which would later appear in build 8130). The former, however, would not be utilized in mainline builds until around build 8008. The Charms bar seen in various sections of the video, logon screen and the Internet Explorer application appear identical to the one seen in the official Developer Preview build. The Start screen is much closer to the variants seen in build 8056 and in the  compile of build 8064, and appears identical to the one shown off in the Computex 2011 demo build, which was demonstrated by Mike Angiulo on 3 June 2011.

The lock screen, compared to the next available build, features an earlier design iteration which displays the date above the clock.