AppleXml - Raymond Yee's Wiki

This Technical Note contains the schema describing the XML file format used by Keynote documents (refered to here and in later documents simply as "APXL" -- Apple Presentation XmL). It is intended for developers who wish to create or modify Keynote presentations programmatically.

Apple uses XML for new presentation format, but shuns SVG

Can't find details about iPhoto/iLife XML

Apparently, iPhoto has an XML format for its albums, in a file named AlbumData.xml. (I haven't been able to find any documentation on that format though. Apparently, iLife uses XML throughout the suite (witness such discussions). However, I can't find any docs...