ActivityPub federated network of people's personal blogs for generating links to similar articles by other people with whom the blog owner federates. Not a blog platform itself, just some code that can be put into a CMS or even plain HTML blog. Maybe a REST API that folks can host on their own equipment?
Cybrespace is an instance of Mastodon, a social network based on open web protocols and free, open-source software. It is decentralized like e-mail.