RSS (which, in its latest format, stands for "Really Simple Syndication") is a family of web feed formats used to publish frequently updated content such as blog entries, news headlines or podcasts. An RSS document, which is called a "feed", "web feed", or "channel", contains either a summary of content from an associated web site or the full text. RSS makes it possible for people to keep up with their favorite web sites in an automated manner that's easier than checking them manually.
RSS content can be read using software called a "feed reader" or an "aggregator." The user subscribes to a feed by entering the feed's link into the reader or by clicking an RSS icon in a browser that initiates the subscription process. The reader checks the user's subscribed feeds regularly for new content, downloading any updates that it finds.
The initials "RSS" are used to refer to the following formats:
- Really Simple Syndication (RSS 2.0)
- RDF Site Summary (RSS 1.0 and RSS 0.90)
- Rich Site Summary (RSS 0.91)
RSS formats are specified using XML, a generic specification for the creation of data formats.
RSS is a format for syndicating news and the content of news-like sites, including major news sites like Wired, news-oriented community sites like Slashdot, and personal weblogs. But it's not just for news. Pretty much anything that can be broken down into discrete items can be syndicated via RSS: the "recent changes" page of a wiki, a changelog of CVS checkins, even the revision history of a book. Once information about each item is in RSS format, an RSS-aware program can check the feed for changes and react to the changes in an appropriate way.
RSS-aware programs called news aggregators are popular in the weblogging community. Many weblogs make content available in RSS. A news aggregator can help you keep up with all your favorite weblogs by checking their RSS feeds and displaying new items from each of them.
So which one do I use?
There are 7 different formats, all called "RSS". As a content producer who wants to make your content available via syndication, which format should you choose?
RSS versions and recommendations
Version |
Owner |
Pros |
Status |
Recommendation |
0.90 |
Netscape |
|
Obsoleted by 1.0 |
Don't use |
0.91 |
UserLand |
Drop dead simple |
Officially obsoleted by 2.0, but still quite popular |
Use for basic syndication. Easy migration path to 2.0 if you need more flexibility |
0.92, 0.93, 0.94 |
UserLand |
Allows richer metadata than 0.91 |
Obsoleted by 2.0 |
Use 2.0 instead |
1.0 |
RSS-DEV Working Group |
RDF-based, extensibility via modules, not controlled by a single vendor |
Stable core, active module development |
Use for RDF-based applications or if you need advanced RDF-specific modules |
2.0 |
UserLand |
Extensibility via modules, easy migration path from 0.9x branch |
Stable core, active module development |
Use for general-purpose, metadata-rich syndication |
Our RSS feed will up and running within the next 2 weeks |
