Microsoft's free software for synchronizing data between Windows computers and Microsoft Outlook and handheld computers and mobile phones based on Windows Mobile and Windows CE. With ActiveSync, you can synchronize email, contacts, calendar, tasks, notes, documents, photos, music and videos. The program automatically detects compatible devices and allows you to exchange data via USB cable, serial cable, Bluetooth or infrared connection.

In addition, ActiveSync allows for direct synchronization with Exchange Server 2003, so that Outlook data (mail, contacts, etc.) can be synchronized. Users of older Windows 98SE and Me operating systems can use the latest Polish version (3.7.1) of the program running under the control of these systems. ActiveSync 3.7.1 PL is available for download on the manufacturer's website.

The program cooperates with Microsoft Outlook 2000, 2002 (XP) or 2003 (recommended) versions. For proper operation of the program it is required to be installed in Internet Explorer 6.0 4. For proper operation of the program a mobile device working on the basis of one of the following systems is required:

- Microsoft Windows Mobile 5.0 - Messaging and Security Feature Pack for Microsoft Windows Mobile 5.0 - Microsoft Windows Mobile 2003 Second Edition - Microsoft Windows Mobile 2003 - Microsoft Pocket PC 2002, Microsoft Windows CE OS version 3.0 - Microsoft Smartphone 2002, Microsoft Windows CE OS version 3.0.