is a commenting system,
which you can add in an
<iframe> below your blog posts,
after having installed Remark42 on a server of yours (there's no SaaS).
Remark42 is more light-weight than Talkyard (you can use a cheaper server).
Both Remark42 (https://github.com/umputun/remark42) and Talkyard are open-source.
Talkyard has some features useful for larger discussions that Remark42 lacks. And can function also as a discussion forum, should you want that. There's a hosted option (SaaS) if you don't want to manage your own server.
Price and Hosting
If on-premise. SaaS always auto upgrades.Yes