"Explaining RSS is like explaining sex. You just don't get it until you do it." - George Siemens (2003)
Syndication, and the syndication protocol known as RSS (for "really simple syndication"), has become a very popular adjunct of blogs (see also the section on blogs in this book). RSS allows blog authors (or anybody else) to distribute their new content to topic-focussed "channels" and for blog readers to "subscribe" to such channels. In practice this means that I can, for example, stay up to date with what a whole range of blog authors have been saying about e.g. collaborative learning, without the hassle of having to read each author's blog (including their musings on all sorts of topics I am not interested in). RSS is a very simple XML mark-up system, so it is relatively easy to make one's content available in RSS-encoded form (i.e. to create an "RSS feed"). To read RSS-encoded content, one can either simply visit a website which aggregates RSS feeds relating to a topic one is interested in or use a desktop program such as AmphetaDesk or FeedReader (or check out this long list of RSS readers).
Introductions to RSS
Brian Lamb's (2003) "RSS: A Love Story" is a short, sweet explanation of why RSS is nice.
Mary Harschh (2003) has written an interesting article on RSS: The next killer app for education. She lists several useful ways of using RSS in education, although they are mainly of the one-to-many content-broadcasting variety. In the context of collaborative learning, syndication is perhaps most interesting because it facilitates (as is illustrated in the world of blogging) the formation of smaller interest groups within a larger distributed system, with each participant in the system typically belonging to several interest groups - so that there is much overlap among groups, but no single large group.
The first part of Eva Kaplan-Leiserson's (2004) RSS: A learning technology (published in Learning Circuits) is an introduction to RSS, but the second half contains many pointers to how RSS can be used in distributed collaborative learning environments in place of cumbersome, centralised Learning Management Systems.
Where to find RSS feeds
Many sites, especially blogs have a link to their RSS file, often in the form of an orange RSS or XML button. Copy this link into your RSS reader and the reader will start checking it periodically. There are also many directories of RSS feeds, such as:
Syndic8 which had almost 100 000 feeds in their directory in early 2004.
iUpload's MailbyRSS is an interesting free service that converts e-mail to RSS - so if you can send e-mail you can have an RSS channel. It is especially useful to people who send out e-mail newsletters and want to give subscribers an alternative means of receiving it. They simply sign up with MailbyRSS, get a special e-mail address and then start sending the newsletter to that address. This creates an RSS feed, with each new edition of the newsletter added to the top of the feed. Another use for it is in conjunction with a discussion list - just subscribe the special MailbyRSS address to the list (in addition to the human subscribers) and and it will generate an RSS feed. If I understand it correctly, MailBucket is good for exactly the same thing. Mailfeed is a PHP script (i.e. it is not a service but something you have to install on your server) that will read any POP e-mail inbox and convert it into an RSS feed (so you can read your e-mail in an RSS reader).
myRSS "enables anyone to build custom RSS channels for virtually any news site they desire. myRSS requires no programming experience, is completely automated and all channels are available for free."
Rollup is a wonderful "automated blog that aggregates (rolls up) a number of different sources". So, for example, you can put together the RSS feeds from the blogs of ten people who all write on the same topic and create a meta-blog showing all their posts in one place.
Kinja is similar to Rollup. Users "can create a convenient personal digest, to track their favorite writers."
Blogdigger Groups makes it easy to create a combined blog from a collection of individual blogs (e.g. this blog about comics). The only requirement is that each of the individual blogs have an RSS feed.
XMLMania allows you to instantly set up an xml feed for a Google News search. Just put the URL of the feed in your RSS reader and you'll start getting news items relating to the search term.
"Bloglines is a free service that makes it easy to keep up with your favorite blogs and newsfeeds. With Bloglines, you can subscribe to the RSS feeds of your favorite blogs, and Bloglines will monitor updates to those sites. You can read the latest entries easily within Bloglines. Unlike other aggregators which require you to download and install software, Bloglines runs on our servers and requires no installation."
Yahoo groups provides RSS feeds of messages posted to a group - the RSS address is the same as the group's message archive address, just add the extension "messages?rss=1".
A key promise of RSS is that individual RSS feeds with similar content can be aggregated so that one can subscribe to these aggregate channels rather than to dozens of individual channels. The internet topic exchange (http://topicexchange.com/) has a growing collection of aggregate channels of this sort, as has Stephen Downe's edu-RSS (http://www.downes.ca/cgi-bin/xml/edu_rss.cgi). S�bastien Paquet (2003) identifies a number of basic operations that can be performed when feeds are combined:
Splicing (union): I want feed C to be the result of merging feeds A and B.
Intersecting: Given primary feeds A and B, I want feed C to consist of all items that appear in both primary feeds.
Subtracting (difference): I want to remove from feed A all of the items that also appear in feed B. Put the result in feed C.
Splitting (subset selection): I want to split feed D into feeds D1 and D2, according to some binary selection criterion on items.