[Wilya]

Frankly, except for the people developing the readers, the RSS/Atom distinction is completely irrelevant. RSS is used as a simplification for RSS/Atom.

I am actually developing a reader, so I know the differences. They're mostly minor, and I have to support both formats anyway, so I abstract most of them away.

[pnelson]

Most are minor but Atom feeds explicitly state content type. This could be a security issue with RSS since there is no reliable way to guess between plain text or escaped HTML.

http://en.wikipedia.org/wiki/Atom_(standard)#Content_model