Monday, May 12, 2008

News Feeds - RSS and Atom

I was half way through a final edit on another article for the blog when I realised that some people might not understand exactly what was happening "under the hood." with all this information being passed between websites and from websites to a News Reader. The key to this are some formats known as RSS and Atom.

RSS is the earliest of these formats, now it stands for Really Simple Syndication. Atom is a replacement that was pushed to try and get over some confusion and splitting surrounding the RSS format. These formats are designed to allow a standard way to encapsulate and describe bits of information so that one piece of software can publish it and another piece of software can read it. An RSS feed contains not just the text of a blog post but the title and date that it was posted. Instead of the text it might be a video, picture or audio file. A podcast is just an RSS feed that contains audio instead of text.

Why is this important?

As you may be aware, it is easiest to write computer software when what you need to do is predictable and simple. Now go and visit a few web sites - go to the front page of your daily newspaper, two of your favourite web logs and one or two others. Notice how the layout can vary tremendously; different fronts, different places on the page for various information. Underneath the source code for the page can vary even more. This makes it almost impossible to write software that can find the information needed to check if a new story has appeared and extract it from the page. Essentially an RSS feed is another web page, with identical information to the site, just laid out in a predictable, standard way so that it can be easily read by software.

Subscribing to a feed

When you visit a web site, particularly a blog or news site you may see in the right end of the address box a small icon that looks like this :)) - or you may see the icon on a web page. This is the RSS icon that shows a site has a feed that can be used by a reader. Most web sites with a feed also describe it in a standard way in the headers of the web page that we can't see but can be read by reader software.

I use an online news reader from Google called "Google Reader" as I also use several other Google services and only need to log on once. I also find the ability to "share" an interesting item from Google Reader useful. Subscribing is easy, I added a "Subscribe..." bookmarklet to Firefox (Google provide it for you) and when I find a site full of good nformation I just click on the bookmarklet.

Advantages

The first advantage of using a news reader and subscribing is that it enables you to quickly check a large number of websites, much faster than visiting each site, and you don't need to remember which sites you have visited and when - the feed reader remembers which information you have already read.

The other power of RSS

Finally, RSS is used by other websites to keep an eye on what's happening. There are sites that will gather together the information on what you are posting in various places and show it all in one spot. In my next post I'll be showing you one of these - FriendFeed - and how you can use it to improve your online presence.

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