Just to draw more attention to the point, it's not an unrelated project simply "using the Mermaid name," it's a for profit project started by the creator of mer

Just to draw more attention to the point, it's not an unrelated project simply "using the Mermaid name," it's a for profit project started by the creator of mermaid.js, which charges for some advanced tooling around the opens source project. It's a common enough paradigm to see and in my opinion a pretty virtuous way to fund open source development. See also Redis labs, Gitlab, ElasticSearch...