Treedown is a Domain Specific Language (DSL) for syntax trees. The core of Treedown is equivalent to traditional bracketed notation.
See http://jonathanrobie.biblicalhumanities.org/blog/2017/05/12/lowfat-treebanks-visualizing/ for an introduction to Treedown. A specification is under development, the repository currently contains marked up texts and issues.
This repository will be used to create tooling for Treedown, gather use cases, and agree on how specific constructs should be modeled.