Syndicating Content, Aggregating Comments (alternatives to Disqus)

I’m getting ready to start a new blog – with a specific intent of building a community around it. My first thought is to start with a wordpress site, and syndicate the content through multiple channels.

But… the ultimate goal is that comments & discussion all go to one place – which I’d like to host.

As I understand it, if I simply publish an RSS feed, comments end up on the individual sites that pick up the feed. I can embed Disqus, and then comments all go to Disqus. Any thoughts on some open source software, that I can host, that behaves like Disqus?

Thanks!