After the add-on has imported and indexed the user's contact data, it becomes available to the user through an integrated contact management tool that functions like an address book. One of Mozilla's first experiments is an autocompletion feature that allows users to select a contact when they are typing an e-mail address into a Web form.
To make the browser's contact database accessible to Web applications, the add-on uses the W3C Contacts API specification.
ARS Technica : http://arstechnica.com/open-source/news/2010/03/mozilla-labs-builds-add-on-to-bring-addressbook-to-firefox.ars
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