James Routley

Draft: started 2026-04-10 • Tagged /atom, /rss

My feeds are Atom feeds.

Everyone with knowledge agrees that Atom is technically superior to RSS.

Unfortunately, many people continued to write and choose RSS,

Most of the differences are surface-level, or in practice not a problem:

RSS uses a stupid date format? Doesn’t really affect people much.
RSS doesn’t specify content encoding, so it’s ambiguous as to whether <description> is text or HTML?
RSS is a travesty and the name refers to nine mutually-incompatible formats, published by a variety of different and competing organisations sometimes even using the same version numbers?

But what few realise is that some of the differences matter.

So let’s talk about the cases that matter.

Title encoding semantics

Précis: you can’t reliably use characters like < or & in RSS titles.

Content management systems normally allow headings to contain markup;

Atom defines something called text construct,

In RSS… well, not even content gets encoding semantics,

Suppose you want to encode this title:

All about the <xmp> element

How are you going to do it?

In Atom, you have three clear choices:

Discard the markup, and encode the text as text.

<title type="text">
	All about the &lt;xmp> element
</title>

Keep the markup, and entity-encode the HTML.

<title type="html">
	All about the &lt;code>&amp;lt;xmp>&lt;/code> element
</title>

Keep the markup, and represent the HTML as XML.

<title type="xhtml">
	<div xmlns="http://www.w3.org/1999/xhtml">
		All about the <code>&lt;xmp></code> element
	</div>
</title>

TODO: survey RSS readers to find out how they handle all of these cases.

Hard mode challenge: <_>::v::<_>, a real title I used.

RSS bad, Atom good. Capiche? 😁

Heuristics, bad for interop, &c. &c.

I feel like there was a third Difference that Matters that I had in mind at some point. Maybe I’ll remember it before I publish.

I must, in good faith, mention podcasts.

Since this stuff is largely from 20–25 years ago,

Rough timeline:

So I want to blame Apple.

RSS is a mess. Podcast RSS is even more of a mess.