wojciechpolak parent
How this relates to WebSub (previously known as PubSubHubbub)? https://www.w3.org/TR/websub/
As far as I am aware WebSub has more or less completely obsoleted RssCloud.
Source: I run a feed reader service that supports WebSub and when I checked none of our subscriptions support RssCloud but not WebSub.
I would be interested in know what your feed reader service is, and how subscriptions support WebSub.
My feed reader service is https://feedmail.org. The simplest instructions for WebSub are those on the public Google hub https://pubsubhubbub.appspot.com/. But there are other public hubs available or you can run your own.
Came to ask this as well. It seems like a competing solution to the same problem.
rssCloud is a separate protocol, but performs many of the same functions as WebSub.