I don't disagree here. At the moment, moon leans closer to a task runner, with hashing, incremental caching, and other features tacked on. All of our currently supported languages are not compile based languages, and run with pre-built binaries.

Once we starts supporting more languages, especially compile based ones (probably Rust first), our decision around YAML will probably change. Off the top of my head, a non-YAML format would probably be used as a secondary format, kind of like how a Dockerfile works.