If you've visited my site before, you might notice it's different now. It's a complete forum -- the blog part is done through permissions.
The structure is a tree and based on discussion at https://curi.us/2396-new-community-website-features-and-tech. It's highly customizable and supports things like CNAMEs for sub-forums (which can be ~disconnected from the main forum tree via permissions).
Every node in the tree supports RSS feeds. Hit the RSS button or add .feed to the end of a URL to get the feed.
I've made an Open Discussion node at /n/88 -- you can post whatever there.
Nodes can be viewed as any other type of node; atm there are 3 types: root, index, and topic. Add /as:<view> to the end of a node's URL to view it via that method, e.g. https://xk.io/n/0/as:topic. The main forum-nodes have descriptions but -- atm -- those aren't shown except via view-as or the RSS feeds.