At the risk of getting down-voted for self-promotion... For self-hosting try https://github.com/documize/community https://github.com/documize/community -- WYS

At the risk of getting down-voted for self-promotion... For self-hosting try https://github.com/documize/community https://github.com/documize/community -- WYSIWYG or Markdown, integrate data from Trello, GitHub, or roll your own integration. Still early days yet, but you should get a feel for docs/wiki/SaaS data embedding.