Outside those who physically own a Surface Hub, not many have had the chance to try out the edition of Windows 10 that the Surface Hub is shipped with. It's an altered SKU of Windows 10 designed for the big screen, with productivity in mind and hooks up directly to business domains and azure.
If you've been looking to try out a build of Windows 10 for the Surface Hub, today's your lucky day. A partner build of Windows 10 for Surface Hub has leaked online in ESD format, meaning it'll need to be converted into ISO format before being install-able. The leak appears to have originated from Microsoft's own Windows Update servers.
The build in question is 14371, which isn't exactly the newest of builds. It's from the 'rs1_release_prs' development branch however, which builds usually don't come from for Insiders. The leak includes pretty much everything Microsoft has demoed regarding Surface Hub so far, including the altered Start Menu, UI and apps list.
We recommend you do not install this 'leak' as it is pre-release, and you probably don't own a Surface Hub anyway. Although this can be installed on normal hardware, you may encounter issues as expected. And of course, don't install this leak over your primary machine.