I was looking for a human-friendly format to store data for a staticly generated website. Stuff like copy, lists, addresses, contact information (so that the rendering logic is kept separate).
I'm a huge fan of NestedText, especially as there is no escaping needed ever.
If you ever want to use it as a pre-format to generate either TOML, JSON, or YAML, I used the official reference implementation to make a CLI converter between them and NestedText.
When generating one of these formats, you can use yamlpath queries to concisely but explicitly apply supported types to data elements.
Landed on NestedText, and apart from it having few implementations, I loved it! https://nestedtext.org/en/stable/
I did feel like I missed a more popular alternative, because I can't be the only one to want a human-friendly data format.