OPML is a file format that can be used to exchange subscription lists between programs that read RSS files, such as feed readers and aggregators.

Jon explains how to use Firefox and Sage to import an OPML file into Safari. My question is, why not just use Firefox and Sage? Just joking! Nice tip.

The XML files are parsed on the server. It generates Javascript data. This data is then loaded into the page through an iframe. When an XML branch is encountered (OPML/XML/RSS), then the file is automatically loaded into the tree.

News, Technology, Internet, Software, Sports, Blogs...remember, each one is an outline or a list of other RSS feeds (also lists). O(n^3) is more like it. Phew! Previews thanks to Sjoerd of w3future.

Danny discusses the possible advantages of transforming an RSS feed list in OPML format into RDF/XML using XSLT. And in particular to utilize "tags" to create a hierarchy of relationships. Why the all fuss? RDF is a lot more powerful than simple OPML.

Import (upload), manage (edit), share and export your OPML file using nothing but your browser. Editing is a snap, the service allows you to expand and collapse branches of your list, and right click each node to access an add, delete, move and edit menu.

It works like you think it should. You submit the URL of an OPML document, and it checks to see if it conforms to the XML specification, after that the OPML spec, and then the OPML Validation Guidelines.

This early version of a dedicated OPML Search engine public service has been created in the spirit of creating something of value to the OPML and podcasting community.

A Web-based integrated service for creating, hosting and publishing OPML files. They may be uploaded from your desktop or a URL, source code pasted, or converted from PowerPoint files. Lists may be private, public, or even editable in a Wiki environment.

A three part tutorial covering the OPML text, link and RSS elements. The first tutorial provides an overview of the section and its metadata elements. Adam provides plenty of example code, and uses the Optimal Browser to display the results.