As you can see in the right nav, I’m now offering two different “feeds�? for my site, Atom
and RSS
. Having both may prompt you to ask “What’s the difference? Why have both? What are they for anyway?�?
What you need to know is that they do the same thing. They allow Internet users subscribe to a “feed�? from a web site. By subscribing to a feed, a user can be notified when a website has been updated. More on this here.
The whole RSS vs. Atom history is rich and interesting, but I’ll spare you. Just know this: RSS came first, it worked, but was deemed imperfect by many. Updated: Be sure to check out Dave Winer's Version History of RSS.
However, the RSS concept was so good that it brought together a wide variety of developers and companies to develop a new syndication format that would benefit everyone equally. This new format is called Atom and you could call it a competitor to RSS.
So, there are now two basic formats for syndicating a web site. RSS is older with many different versions, Atom is newer, more standard, and only beginning to be adopted. Atom was constructed to work across a wide variety of platforms and devices.
I offer both so that I do not exclude any user from subscribing from my site. I would personally like to see Atom become the leading format because it is built by a diverse community who “baked-in�? the ability for Atom to evolve with consistency over time.
For more info:
The Atom Wiki (motivation page)
Webmonkey: Mighty Atom -Really Similar Syndication?
Atom Enabled.org
If you are a Movable Type user, you can get the Atom index template from the site.