[…] The ability to find and access WebDAV file shares is likely to become a primary feature of iOS 5.0 this summer. Right now, iOS devices are limited to using iTunes File Sharing to copy files between iPhone or iPad apps and a desktop computer, or users can simply email files as attachments. It’s currently not possible to upload files via Safari, nor is it possible to download most files over the web to save locally (outside of photos).
Apple also uses the open WebDAV protocol as the basis for its Address Book Server for contact sharing and corporate address books, and its iCal Server for shared calendaring on Mac OS X Server; each use an extension to WebDAV, named CardDAV and CalDAV, respectively. iOS already offers support for these protocols, but hasn’t yet adopted full support for push updates. […]
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http://forums.appleinsider.com/showthread.php?t=121222
