added A common persistent metadata abstraction
What is the problem you are trying to solve?
GNOME doesn't have a common way to manage metadata, if you add a tag to a photo via F-spot you can't browse the photos with that tag with Eog, Nautilus and viceversa.
Pippo stores his photos on the hard disk, some photos are tagged with the name of his friends and when he decide to burn the photo on a CD he doesn't want to lose the metadata written.
Paperina loves trekking and she make a photo of the most beautiful places visited, she would like to add persistently the coordinates to her photos without use Flickr or other Web2.0 services
Pluto tags pdf, mp3, ogg, mp4,.. and he would like that the files that support persistent metadata inherit the tags value
GNOME applications that use/plan/could/ to access to metadata
Nautilus (all kind of files that supports persistent metadata)
Rhythmbox (music ID3)
Totem (music ID3,video dependent by container MP4, Matroska MKV , MOV,..)
Eye of GNOME (image example import EXIF, IPTC and write in XMP)
Evince (document xmp in pdf)
Describe your Idea/Solution
I don't know which is the best place to have a metadata abstraction, anyway GNOME should choose a default persistent metadata type for images (EXIF. IPTC, XMP), the unique format that the metadata are written on the file, and various importers for the other ones.
Other pages on the wiki
http://bugzilla.gnome.org/show_bug.cgi?id=401664 or search iptc xmp exif on bugzilla http://blogs.msdn.com/pix/archive/2006/08/16/702780.aspx http://freedesktop.org/wiki/Specifications_2fshared_2dfilemetadata_2dspec http://wiki.creativecommons.org/XMP http://f-spot.org/Imported_tags KDE4 and metadata http://liquidat.wordpress.com/2007/05/31/semantic-desktop-and-kde-4-state-and-plans-of-nepomuk-kde/#comment-22552
see also GnomeIdeas