Atom is one name for two things: It's both a new standard for developers, as well as a syndication format or "feed" for your blog. When a regularly updated site such as a blog has a feed, people can subscribe to it using software for reading syndicated content called a "newsreader." People like using readers for blogs because it allows them to catch up on all their favorites at once. Like checking email—without the SPAM.

at•om (at'em)
n.

1. An Application Program Interface.
2. Your blog's new syndication feed.

More than two years ago we published an experimental Application Programming Interface for Blogger. Developers and vendors were able to work with the BloggerAPI despite various drawbacks, but it was in need of an overhaul. Some engineers active in the tech/blogging community began working on a better, more comprehensive concept code-named Atom. This new system looked as though it could solve a lot of problems with our API, as well as establish a universal syndication format. Atom has finally arrived, and that means different things to different people.

What Atom Means to Blogger Users

Atom provides the potential to share your blog with a wider audience. When you activate Atom syndication, Blogger automatically generates a machine-readable version of your blog that can be picked up and displayed in a variety of ways, including newsreaders, web sites and handheld devices. There are already a bunch of newsreaders that support Atom, including NewsMonster, NewzCrawler, NewsGator, NetNewsWire, Shrook, RSSOwl and BottomFeeder. You can find a growing list of newsreaders at AtomEnabled.org.

See: How Do I Change My Site Feed Settings?

Atom touches more aspects of blogging than just blog-reading. That means it will be easier for developers to come up with applications that help you create, edit, publish, and archive your blog in a variety of new ways or just come up with stuff they think is cool, useful or fun. After all, that's how Blogger was created in the first place!

What Atom Means to Developers

AtomEnabled.org proclaims: "AtomEnabled finally makes it possible for developers to have a consistent, tightly specified, well-documented XML format for both syndication and authoring of content. Using one data format for both reading and writing, with a growing library of components supporting Atom development in almost any major scripting or programming language, means your application, site, or device can benefit from the network effect of a large community while spending less time developing core data exchange functionality."

So if you're a Developer, that meant something to you and you are looking forward to using this data format to develop cool stuff for the rest of us. We're looking forward to that too. Please check out the Developers area of AtomEnabled.org for specs and information. Also, watch the Blogger Developer blog for information specific to Blogger.

What Atom Means to Everyone

Ultimately, Atom is not just for bloggers and developers, but for everyone. As a universal format for personal content publishing built on a platform that is very extensible, Atom will allow the easy flow of information to and from the Web and beyond. Yes, Atom comes from a bloggy crowd, but that's just because the blogosphere is such fertile soil for innovation. Thanks to everyone who put in a lot of hard work to bring Atom to life. We look forward to great things.

Source: http://help.blogger.com/bin/answer.py?answer=42014