OPML is defined in Wikipedia as “an XML format for outlines” [1]. OPML stands for Outline Processor Markup Language. It was originally developed as an outlining application by Radio Userland. However it has been adopted for a range of other applications, in particular providing an exchange format for RSS.

Why The Interest?

Grouping Feeds

As an example of the user benefits which OPML can provide let us look at the various RSS feeds which are available on the BBC Web site. These include RSS feeds for:

• News items
• Sports
• TV programmes
• Regional items
• Podcasts
• …

In each of these areas there might be multiple additional feeds. For example the Sports feed could provide general news covering all sports, with additional categories for individual sports. Then might then be news feeds for individuals sports teams.

OPML provides a mechanism for grouping related RSS feeds, allowing them to be processed collectively rather than individually. This can be particularly useful if you wish to subscribe to a group of feeds. An example of how the BBC make use of OPML files for their podcasts can be seen at [2].

Export and Import of Feeds

OPML can also be used if you wish to migrate your feeds from one RSS reader/aggregator to another.

Examples

User Interface to Resources

Use of the Grazr widget on the UKOLN Cultural Heritage Web site [3] is illustrated.

In this example RSS feeds have been created for all the briefing documents, new briefing documents and other lists of resources. These RSS feeds are described in an OPML file. The Grazr widget then allows these files to be navigated and once a suitable resource has been found it can be opened in the Web browser window.

Netvibes and Google Reader

As illustrated, RSS readers such as Reedreader allow RSS files to be imported and exported as OPML files.

This can be useful if you wish to migrate large numbers of RSS feeds from one RSS reader to another.

This may also be useful if you wish to share your list of RSS feeds with other users.

An example of a similar interface in the Google Reader is also illustrated.

The ability to easily migrate data between applications not only provides greater flexibility for the user, it also minimises risks of data being trapped into a particular application.

References

1. OPML, Wikipedia,
   <http://en.wikipedia.org/wiki/OPML>
2. OPML feed of podcasts, BBC,
   <http://www.bbc.co.uk/blogs/radiolabs/2008/04/opml_feed_of_podcasts.shtml>
3. RSS Feeds, Cultural Heritage, UKOLN,
   <http://www.ukoln.ac.uk/cultural-heritage/rss/>

RSS is defined in Wikipedia as “a family of Web feed formats used to publish frequently updated works – such as blog entries, news headlines, audio and video – in a standardized format” [1]. RSS and the related Atom standard can be used to provide alerts and syndication of content. These lightweight standards play an important role in a Web 2.0 environment in allowing content to be easily reused.

How RSS and Atom Are Being Used

News feeds are an example of automated syndication. News feed technologies allow information to be automatically provided and updated on Web sites, emailed to users, etc. As the name implies news feeds are normally used to provide news; however the technology can be used to syndicate a wide range of information.

Examples of use of RSS on organisational Web sites include:

• The Forestry Commission Scotland which provides RSS feeds for news and information on trail conditions [2]
• The Old Operating Theatre and Herb Garret which provides RSS feeds for information on news, events, grants received and development plans [3]
• The Kids and Reading service which provides RSS feeds on latest articles and news [4]

RSS and Atom are widely used by popular Web 2.0 services, allowing the content provided by the services to be viewed without the user having to visit the service. Examples include:

• Amazon which provides RSS feeds on the availability of new products [5]
• Flickr which provides a variety of customisable RSS feeds [6]
• YouTube which provides a variety of RSS feeds about various categorised groups of videos[7]
• The BBC which provides a large numbers of RSS feeds covering the range of its services [8]

RSS Feeds Readers

As described in [9] there are a large number of RSS reader / RSS aggregation tools available. Examples of different types of RSS readers are summarised below.

• Google Reader: Google Reader [10] is an example of a popular Web-based RSS reader.
• Newsgator and NetNewsWire: Netnewswire [11] is an RSS client for the iPhone/iPod Touch mobile devices which is integrated with the Newsgator Web-based RSS client.
• Netvibes and PageFlakes: Netvibes [12] and PageFlakes [13] are Web-based RSS readers which provide a more graphical style of interface than Google Reader.
• Feedreader Feedreader [14] is an RSS reader for the desktop.
• Outlook 2007 Email Client The Microsoft Outlook 2007 email client [15] includes an RSS reader. This will enable you to read RSS feeds in a similar fashion to reading email.

References

1. RSS, Wikipedia,
   <http://en.wikipedia.org/wiki/RSS>
2. Forestry Commission Scotland,
   <http://www.7stanes.gov.uk/forestry/INFD-6ZGJZM>
3. The Old Operating Theatre and Herb Garret,
   <http://www.thegarret.org.uk/rssfeed.htm>
4. Kids and Reading Service,
   <http://www.kidsandreading.co.uk/>
5. Product RSS Feeds, Amazon,
   <http://www.amazon.com/Product-RSS-Feeds/b?node=390052011>
6. Flickr Services, Flickr,
   <http://www.flickr.com/services/feeds/>
7. About RSS, YouTube,
   <http://www.youtube.com/rssls>
8. News Feeds From The BBC, BBC,
   <http://news.bbc.co.uk/1/hi/help/3223484.stm>
9. Aggregator, Wikipedia,
   <http://en.wikipedia.org/wiki/Aggregator>
10. Google Reader, Google,
    <http://www.google.com/reader/view/>
11. Online News Reader, Newsgator,
    <http://www.newsgator.com/individuals/>
12. Netvibes,
    <http://www.netvibes.com/>
13. Pageflakes,
    <http://www.pageflakes.com/>
14. Feedreader,
    <http://www.feedreader.com/features.php>
15. Get Your RSS Feeds For Outlook, Microsoft,
    <http://office.microsoft.com/en-us/help/HA102148541033.aspx>