TheBrain
Authored by:: Brendan Langen
This video gives a basic intro to TheBrain. It has a graphical and textual interface for navigating and editing your documents.
Within the graphical interface, it occasionally uses a DSL. For example, creating many branching nodes is similar to writing out the cells of a csv, except you separate nodes with a semicolon.
For a comparison with Roam Research, see the following video from Matt Goldenberg.