Riv is a wiki, but feels like more of a notebook. Think Deft for Emacs with journaling and HTML publishing. What makes Riv interesting — aside from the Vim thing — is that it uses reStructuredText for its native format.
It works well enough, especially once you build up muscle memory for Riv’s leader sequence C-e. Don’t overload it right away though! It includes some insert mode mappings, which can get real confusing if your preferred leader is a space.