Live-Ask - A one-stop solution for moderating discussions and Q&As.
Sitecake - Drag and drop CMS for HTML websites. It's flat file CMS so it's pretty fast.
Whale - Video Q&A with influencers and experts ๐ณ
Anchor CMS - Free and lightweight blogging system
Ask Me Anything - The official Reddit AMA app
Textpattern - Textpattern is an elegant content management system that is free, open source software.