High Quality Content by WIKIPEDIA articles! ActiveSync is a mobile data synchronization technology and protocol developed by Microsoft, originally released in 1996. There are two implementations of the technology: one which synchronizes data and information with handheld devices with a specific desktop computer (originally known as Handheld PC Explorer), and another technology, commonly known as Exchange ActiveSync (or EAS), which provides push synchronization of contacts, calendars, tasks, and email between ActiveSync-enabled servers and devices.