Aggregate RSS and Atom information using XQuery

The Really Simple Syndication (RSS) and Atom standards provide XML
structures of items for a variety of different uses. The most common
use for both RSS and Atom feeds is as the data dissemination format to
promote Weblogs and news sites. The RSS and Atom feeds contain relatively
small amounts of information. Thus, you can easily download the files
and reduce the load on the Web servers rather than supply all of the
information normally distributed when the user views a full page of blog
posts. In addition, the RSS and Atom files also contain more detailed
classification information such as author, title, subject and keyword
tagging information to help identify and organize the data within the
feeds. In this article we look at the basics of XQuery processing of
RSS and Atom feeds to turn a single feed into an HTML document. We then
produce a more complete solution for outputting the information in a
format that suits your needs, including sorting, merging multiple feeds
and even handling different feed and source information types. XQuery
offers a flexible method to process XML files. Some find this method is
easier to follow syntactically. Certainly some XQuery abilities, such
as the flexibility to create to a single intermediary XML document that
you can reparse to handle different sources and input formats, help
solve some issues experienced when you process XML files.