Z-push
Mobile data synchronization is becoming increasingly important for many people, and various standards have arisen to perform this two-way copying 'over-the-air'. The most important platforms that can do wireless synchronisation are ActiveSync that is used to communicate with Exchange Server and Research-in-Motion's BlackBerry Enterprise Server (BES). Both solutions require proprietary server-side software from the vendor, therefore limiting the use of PIMs (personal information managers) to either wired synchronization or irritating 3rd-party synchronizers requiring the installation of client software on the PDA.
This is where Open source Z-Push comes in; it is an implementation of Microsoft's ActiveSync protocol which is used 'over-the-air' for multi platform active sync devices, including Windows Mobile and active sync used on Ericsson and Nokia phones. Open source Z-Push enables any PHP-based groupware package to become fully syncable with any ActiveSync-compliant device.
Being an opensource project under the GPL, it allows developers to add their own backend so that Z-Push can communicate with their groupware solution.
Currently, Z-Push is available with only four backends: the IMAP and the maildir backend for e-mail synchronisation, the vCard backend for contact synchronisation and one for the commercial Zarafa package which is sold by allowing full synchronization of E-mail, Calendar and Contacts. We expect that other backends arise in the near future as the opensource community gets to grips with the new possibilities.