A reading list is the organised list of all feeds that a person reads using their feed reader. There are two primary file formats for reading lists, XOXO and OPML (see What is XOXO?). Reading lists are popularly used as an import/export format for moving subscriptions between feed readers. If they are made available online they can also be used as dynamic reading lists.
Dynamic reading lists are reading lists that are aggregated by a feed reader. One folder or module is always updated to contain the most current subscriptions from the reading list. This allows users to subscribe to other users’ reading lists to see what other’s are reading, for example. Directory sites like Share Your OPML (which, as the name indicates, is anti-XOXO) also allow users to share their subscriptions en masse.
Feed readers currently supporting the dynamic reading list concept are:
Dynamic reading lists can be previewed or included as a widget in a webpage using Grazr. Grazr currently only supports OPML, but XOXO is on the todo list.
If you know of any other programs that support dynamic reading lists or other interesting uses for reading lists, please leave a comment below.
If you have any suggestions on how this introduction to reading lists could be clarified, please leave a comment below.
The list of XOXO Developer’s Resources has been updated to include the Outline Classes. Written in PHP4 but with compatability built in for PHP5 this set of classes is designed to be able to parse and create XOXO, OPML, hAtom, JSON, and arbitrary XML documents and fragments. The classes are GPL‘ed.
BoxtheWeb 0.20 has been released, and with it many different new features. One of the most notable, is support for reading lists. Those new to the concept of reading lists may like
this TechCrunch article as a starting point. Basically, the idea is to be able to subscribe to lists of what other people subscribe to. The new version of BoxtheWeb includes ‘subscription boxes’, which allow you to subscribe to XOXO, OPML, or even RSS/ATOM feeds and give a list of feeds referenced. Each of these feeds can then either be previewed or added to your own BoxtheWeb screen.
Each BoxtheWeb account also now publishes a public feed of the its boxes in XOXO and OPML format. This feed can be filtered to contain only feeds or by tag. Boxes may be marked private so that they are not added to this feed. There is no direct mention of the email address anywhere in the URL or the file, only an MD5 hash (although passing an actual address instead of a hash will work, and result in a feed that contains the email address in ownerName). You can see examples of these feeds by clicking the XOXO or OPML links beside ‘Reading List’ in my sidebar.
You can convert your XOXO blogrolls to reading lists, in either XOXO or OPML format, for use in feedreaders. Reading lists can also be easily converted into XOXO blogrolls. The steps to do either are below:
Blogroll to Reading List
- Go to the Outline Converter
- Select the appropriate reading list format from the ‘Output Format’ dropdown box
- Enter the classes that are on your blogrolls, space-separated (ie ‘xoxo blogroll’)
- Check the ‘Simplify’ and ‘Ensure HTML and XML URLs’ checkboxes
- Enter the URL to your blog
- Click ‘Convert’
Reading List to Blogroll
- Go to the Outline Converter
- Select ‘XOXO’ from the ‘Output Format’ dropdown box
- If converting from an XOXO reading list, enter the classes on the list data into the ‘classes’ box, otherwise enter ‘xoxo blogroll’
- Check the ‘Simplify’ and ‘Ensure HTML and XML URLs’ checkboxes
- Enter the URL to the reading list or cut-and-paste in the reading list data
Note that the Outline Converter outputs the application/xml header for either OPML or XOXO data. XOXO data will thus not render directly in your browser as XHTML, but it is still valid data.
XOXO is a microformat for the storage and transmission of outline data. Outline data is any nested list information, where you have nodes with subnodes. The specification is similar in purpose to OPML, but has many advantages over that format, including :
- XOXO can be embedded completely within any XHTML document. Since XOXO is really a subset of XHTML, it is 100% XHTML-compatible. It can be stored as an independant document, but this is not a requirement as it is with OPML.
- XOXO has predefined fields for common uses. Unlike OPML where all fields are optional/arbitrary and up to individual implementations, XOXO has standardized markup for TEXT, TITLE, HREF, REL, REV, TYPE, and CLASS attributes. One may argue that feed readers have standardized some OPML elements (xmlUrl, for example), however this is not even wholly true (some feed readers use the rssUrl element instead).
- XOXO can be viewed directly in a webbrowser without any need for extra stylesheets
- XOXO can be used to make up the actual content of web pages so that those pages are nice to view, but are also easily read by other applications/scripts
For conveniance, XOXO is still fully extendable, with the ability to contain any number of arbitrary fields.
For more information, see the official XOXO specification and the official XOXO-faq.