Or you could ensure your language supports and defaults to yaml 1.2, so you don't have worry so much. Every language has warts and pitfalls and things that are

Or you could ensure your language supports and defaults to yaml 1.2, so you don't have worry so much. Every language has warts and pitfalls and things that are recommended against. Suggesting that one should abandon such languages, whether full-featured or data-description DSLs, when they're otherwise more productive than the alternatives, is disingenuous. Suggesting that yaml offers no genuine advantages? JSON is annoying. It requires good editor syntax checking support to avoid mismatched and trailing punctuation. It lacks comments. I could live without the nice syntactic sugar of yaml, and even its lack of references and line-folding, if it weren't for those other things. Which leaves something like cfg or json5, both of which have less support than yaml 1.2. So wth are we talking about? Don't use perhaps the best available (human-editable, inline-nested) data DSL because it might not be supported in some language, and because it has a few potential footguns just like json does? toml may be clean, but it's not as easy to deal with because of how it represents nested structures (which aren't fully inlined like they are in json or yaml), as so many people on this thread have pointed out. There's a reason so many modern tools use yaml. It's not that their authors weren't aware of json. Plenty of people are simply more sick of json's problems, and consider yaml a superior, not perfect, alternative.