Every programmer has opinions about configuration files. These opinions tend to be strongly held and inversely proportional to the stakes involved. In the last few years, the consensus view has shifted: YAML is bad, TOML is good, and enthusiastic users of YAML just might be plainly uninformed. This post takes a different view. We intend to present an argument for YAML which is grounded in history, its specification, and the state of tooling in 2026.
This is a companion discussion topic for the original entry at https://opensource.posit.co/blog/2026-05-21_in-defense-of-yaml/