Microsoft is PROBABLY CORRECT. Active Directory (AD) is a directory service implemented by Microsoft for Windows domain networks. It is included in most Windows Server operating systems. To do the Single SignOn is a major PLUS for this company. I know, I use to do it for banks between mainframe and client servers. MAJOR, MAJOR DEAL! Hello Microsoft! Yes, we are at home!
The f100 is for the EASE solution and Bing/Microsoft is the EDU solution so it doesn't make sense that it would be Microsoft. That said if they are also partnered with Bing/Microsoft that means 2 f100 companies using 2 different solutions!!!