That is basically what Discourse is. It is a forum to facilitate conversations. Use it internally or externally, give your team or community a voice.
Discourse can work really well as a self-service knowledge hub for your fans or users. The collective of users always has the answers to the questions the rest has. People can vote, you can mark solutions as the official answer, etcetera.
Discourse has a nice feature: you can assign topics to people. So you and your team can be a transparent helpdesk. After answering a question or fixing a bug you can mark it as solved.
With the vote plugin, you can use Discourse as an idea generator. Let people come up with ideas, with suggestions, with thoughts and let your community vote. May the best win!
You can use Discourse as a comment system for example Ghost, the blog you are looking at. That way you can have all the conversations with your audience in one place.
Try Discourse for free at Stek.io.