So, what’s the difference between RSS and ATOM ?
There are two answers to the question of “what’s the difference between RSS and ATOM ?” First, there is the technical answer. Second there is the end-user answer. I’ll start with the second.
For the vast majority of end-users today there is very little difference between RSS and ATOM. Both are used as means to get access to information and in nearly all cases that information has been formated into “feeds”. I took a look at my blog statistics and was actually surprised by the ration of RSS to ATOM readers - 250:135. Now, my blog is not a hot bed of traffic so these are small numbers but to be honest, I would have thought RSS was much more prevalent. For technical reasons, which I will get to in a moment, the growing use of ATOM is a good thing.
So, what is the technical advantage of ATOM ? Let’s start by thinking of ATOM and “second generation” RSS. This is not precisely true but many of the reasons for ATOM were direct results of issues that were hard to address with RSS - mostly because RSS was already widely used. In short, it’s hard to change RSS because is is so popular. It may seem strange but that is a big part of why ATOM was initially created. So, “out with the old, in with the new”. We have ATOM.
The big change with ATOM is the focus on interoperability and reuse. For simple feed readers, this is not really important, but ATOM is increasingly being used for computer to computer interactions - data sharing. The more controlled the data format, the easier it is to make two completely separate computers “play well together”. Further, computer programs were no longer just “reading data”. They also wanted to have a method for creating new data, performing updates, and even deleting data. (For the lay person, the technical community call this CRUD for Create, Read, Update, and Delete.) So, the ATOM specification describes the use of HTTP methods GET, POST, PUT, and DELETE. Most system, prior to ATOM, only used GET and POST. For more details, you can get a quick understanding by reading the draft. An advantage of ATOM and it’s use of simple HTTP operations is that most of the internet is already optimized for these types of things. When we consider the billions of internet actions that take place every day, “optimizing” is a big-big challenge so the more that can work with the current internet, the better.
What can you do with ATOM and the HTTP operations ? You could write a blog. More important, you could edit a blog. You could search for a list of artists who have recorded a particular song or search for songs that contain a lyric. Then you could select one title and pay for it and get a link to download it. You could have you computer at home automatically publish updates to your friends or co-workers. You might have a little measuring device in your hot water heater or your air conditioner that provides electric usage to the power company. The power company might send new settings to your hot water heater or air condition to make it conserve electricity. A website could get news from the Associated Press news wire, relevant photos from Flickr, clips from searching blogs, and video from CNN and loads it all into an electronic news paper that refreshes every morning just as your coffee pot finishes brewing. This last one is partially here today using Feed Journal to create a PDF of your blog interests, formatted like a newspaper and the sent to a Kindle digital book and with the structure of ATOM, the reality of the individualized digital newspaper is a programming exercise a high school student could do in less than a day.
Disclaimer: I’m sure, for the technical reader, this post has been a big let down. It may even have been so simplistic that it misrepresented a few things. But technical explicitness was not the the focus. The focus was the “internet minus 1″ generation - those people struggling with what their kids are talking about when they explain the computer and the internet. Everyone needs to get up to speed and even a rickshaw can go 100 miles an hour if you accelerate it enough <grin>
