Why Are People Still Creating RSS Feeds?

Question

...instead of using the Atom syndication format?

Atom is a well-defined, general-purpose XML syndication format. RSS is fractured into four different versions. All the m

Answer 1

If you are asking why the Atom syndication format is not more widely adopted than the various versions of the RSS format, I think it would be difficult to come to an objective answer. A variety of factors like the amount of investment in RSS prior to Atom, the relative ease in implementing RSS versus Atom, and 'marketing' all come into play.

I can, however, think of a few things that should be considered when choosing what syndication format to use in representing resources:

Atom

• Atom is an official Internet standards track protocol.
• Atom has a registered content media type for its feed and entry representations.
• Without the use of syndication extensions Atom tends to be a more robust format, especially in the link relations arena.
• Representing resources using Atom allows you to leverage the Atom Publishing Protocol (AtomPub) to provide a RESTful API.
• The RFC-3339 DateTime format used by Atom is easy to parse.
• There is only one deprecated version of Atom (0.3) you might conceivably have to support.
• Implementing Atom typically takes more time to do correctly than RSS, as there are more restrictions and the technical specification can be a bit dense.

RSS

• RSS is a relatively simple format to implement in a short amount of time.
• There are not as many constraints/rules placed on RSS as there are on Atom.
• RSS is not an official Internet standards track protocol. However, RSS has enough adoption that you can reasonably expect it to be consumable by a variety of clients.
• As there are quite a few 'deprecated' versions of RSS, you might conceivably have to support RSS feeds that vary quite a bit in their formatting details.
• RSS does not have a registered media content type. However enough publishers use the same unregistered content type that it is almost a defacto MIME type.
• The RFC-822 DateTime format utilized by RSS is more difficult to parse as this particular timestamp format allows a lot more possible variation in the format that is still considered valid.
• You will need to extend the RSS format using a variety of published syndication extensions when you start trying to represent resources with complex link relations.

I think it is important to remember that to the end-user, what syndication format you choose to use is not very important, as most feed readers and browsers handle either format equally well. The choice of syndication format however can be very important to the developer, as there are technical details that can impact the software development side of things.