Keeping conversations going on the Web

In his latest AltPlatform post, Brian Hendrickson discusses various “levels” of comment/conversation technologies available on the Web:

• Level 1 – Crossing web site boundaries, Webmention, Mastodon.social
• Level 2 – Hybrid network, publishing feeds but need a reader to follow them
• Level 3 – Internal social networking (Slack, Rocket Chat)

I use Twitter and RSS readers to try to monitor areas I am interested, and items I want to read and comment on. What I would like is to be able to comment easily and keep a conversation going. If there are tools that can help me do that, I want to know about them!