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Joshua Allen wrote:
> OK, is it fair to paraphrase this argument as "RSS works
> fine today, but Atom will enable you to be more flexible
> in seizing new opportunities tomorrow?"
No. That's not fair. RSS does *not* work fine today. It is a
mess and we pay for that mess in every tool that reads RSS.
1. Virtually every RSS reader actually reads at least three
different flavors of RSS and often as many as seven. All of the these
various formats are underdefined in one way or another. Agreement on
what their elements mean is only approximated through a process of
voluminous and expensive back-channel communications. (Note: The RDF
guys *think* that their formats are well defined, however, the reality
is that any format that relies on random namespaced extensions can
hardly be called "defined"...)
2. Common forms of RSS are missing the ability to express
important concepts. For instance, RSS only has a "pubDate" field to
say when an item was created. However, when people update items, they
typically keep the old pubDate value in order to maintain the item's
order in their blogss. The problem, of course, is that this means that
"date" can't be used to imply "age" or even "sequence" in any useful
way since entries being modified today still carry the date of their
original creation. (Atom defines both "created" date and "issued"
date. This allows the distinction to be made.)
3. There are very few commonly shared conventions for
encapsulating HTML content in RSS feeds. Sometimes you get a CDATA,
sometimes the tag soup is just inserted into an element, sometimes, it
comes with enclosing <html> tags, sometimes, it doesn't. Sometimes, it
is split up into two elements (a <description> and a <content>
I could go on... but that would be depressing.
On my site, we constantly process data from over 1 million RSS
feeds (Yes, we've grown a bit in the last week...)and what we see is a
cesspool of badly formed data. It is "just" barely clean enough to do
minimally useful work with it, but that isn't saying very much.
RSS does *not* work today. The best you can say is that RSS
gives us a clear hint of what a "working" system might look like. Atom
is intended to turn that hint into a reality.