Windows 8 and Windows Phone 8 rely on a technology known as Exchange ActiveSync. This technology is the communication protocol that allows applications in Windows 8 and Windows Phone 8 to synchronize email, calendar, and contact information from Google accounts. So it is rather shocking that Google is severely reducing support for it as of January 30.
Though not widely advertised, the ability to access Google-based services through the native Windows and Windows Phone applications is a key selling point. Without this, potential customers who use heavily use Google would most likely choose Android or iOS instead of Windows 8 based tablets and phones.
It should be noted that Google isn’t completely dropping support for Google Sync, their implementation of Exchange ActiveSync. Customers that are currently using the technology may continue to do so for an indefinite time. New customers wanting it will need to purchase a Google Apps for Business, Government, or Education account.
While some may see this as a commercial attack on Microsoft or just a way to make more money, it may simply be part of Google’s long term focus on open standards. The most important of these is IMAP, the Internet Message Access Protocol. IMAP was invented in 1986 as a way to access remote mailboxes. Until the competing POP protocol, IMAP assumes that email messages will be left on the server.
For calendar support, Google is using the CalDAV standard proposed by Apples and Oracle. This standard is based on the iCalendar data format and WebDAV, an “HTTP-based protocol for data manipulation”. This standard was submitted in 2003 and formally published as an RFC 4791 in 2007.
Contact information is accessed in similar fashion via the CardDAV protocol, published in 2011 as RFC 6352. Also based on the WebDAV protocol, this standard uses vCard as its data format.
According to Wikipedia, both CalDAV and CardDAV are already supported by a wide range of servers and client applications. So if Microsoft picks up support for these standards they would not only keep their Google customers happy but also open the door for users of other services.