Reddit has something like this, but definitely not as intentional,
- https://www.reddit.com/r/all/.json
- https://www.reddit.com/r/all/.rss
- https://www.reddit.com/r/all/.xml
>The only thing Reddit has going for it IMO is the uniform UI across communities and they seem determined to make that a crappy experience from what I've seen.
Old reddit had stylesheets and they could be very interesting. I still prefer that over the current thing they built.