OPML and XSLT

OPML is "Outline Processor Markup Language" and is a very simple XML format for storing information in outline format Of course, XML itself is perfect for representing hierarchies, but OPML constrains the format enough that a wide variety of applications can build in OPML support with the comfort of knowing it will work with any other OPML tool For information stored in hierarchies, such as web browser bookmarks, web directories, collaborative outlines, song playlists, and even web-site content, OPML is a great balance between the wide open freedom of raw XML and the feeling of security of a formal vocabulary You should be able to read and understand the very small specification in just a few minutes.