While Microsoft announced a number of new device management features for Windows 8.1 at TechEd 2013, they spent very little time on a new component called Open MDM. Open MDM is interesting in that it removes the Microsoft-centric limitations for managing devices running Windows 8.1.
A lot of larger Microsoft customers utilize System Center components, particularly Configuration Manager and Windows Intune, to manage endpoints. Endpoints include laptops, PCs, servers, tablets, smartphones – really anything that connects to the corporate network. But, some customers have not made the investment in System Center but would still like to manage tablets and BYOD devices as mobile devices.
Open MDM provides an API agent that allows 3rdparty MDM products to still manage devices running Windows 8.1. Some more notable 3rdparty MDM products you may be aware of are Mobile Iron, Air Watch, or Symantec Mobile Management (formerly Odyssey Software's Athena).
Microsoft talked about this feature for Windows Phone in October 2012 and will now be fully realized in Windows 8.1, further aligning their smartphone OS with their desktop OS.