I've been using Mermaid with MediaWiki and it has a lot of promise. Since Mermaid lets me generate diagrams from text and MediaWiki lets me store and modify structured data, I can have MediaWiki pass Mermaid data to generate graphs/diagrams that stay up-to-date as the wiki changes.
I would like to see Mermaid be able to group sibling nodes[0] though, once I can do that, I can autocreate really nice organizational charts :)