So, Dave Winer recently posted about how great it is that Facebook's Instant Articles system is built on open web standards, and I'll admit, reading through the docs makes me love this system a lot more than Google's AMP. It's based on simple HTML5, a custom XML namespace for some classes, and RSS. That's it.
If I had even one complaint about Instant Articles, it's that they're using the
<small> tag for the legal text. It's ironic, but not in the funny way. Still, that's the only complaint I could find.
If you're interested in reading up on it, you should check out the documentation. While I have no plans on using it myself, I'm happy that, unlike Google, they're keeping it simple.