title: Standard ML description: "Configure Standard ML language support in Zed, including language servers, formatting, and debugging."

Standard ML

Standard ML support is available through the community-maintained Standard ML extension.

• Tree-sitter: MatthewFluet/tree-sitter-sml
• Language Server: Millet

Setup

1. Install a Standard ML implementation such as SML/NJ or MLton to compile and run your code.
2. Install Millet and ensure millet-ls is on your $PATH.

Project setup

For projects with more than one source file, Millet expects a single root group file. Create a millet.toml in the directory you open in Zed:

version = 1
[workspace]
root = "sources.mlb"

The root must be either an ML Basis (MLB) file (.mlb, used with MLton) or an SML/NJ Compilation Manager (CM) file (.cm, used with SML/NJ). Files not transitively reachable from the root are not analyzed. See the Millet manual for more options.