Microsoft last week announced sweeping changes to Office's support rules, which will push more corporate customers to the Office 365 subscription model.
The support policies introduced Thursday will cut in half the time that non-subscription versions of Office -- usually labeled "perpetual" as a nod to the licenses which, once purchased, let customers run the software as long as they want -- can connect to Microsoft cloud-based services. These include Microsoft-hosted Exchange email, the OneDrive for Business storage service and Skype for Business, the corporate edition of Microsoft's video-calling service.
Under the new rules, owners of perpetual-license versions of Office will be able to use those services only during the first half of their 10-year support lifecycle, the portion Microsoft dubs "mainstream." Currently, those customers may connect to cloud services such as Exchange mailboxes for the full decade of Microsoft's combined mainstream and "extended" support.