YAML - YAML 1.2 --- YAML: YAML Ain't Markup Language
TOML - TOML - Tom's Obvious, Minimal Language
Messagepack - An efficient binary serialization format.
JSON - (JavaScript Object Notation) is a lightweight data-interchange format
Dhall Configuration Language - A non-repetitive alternative to YAML
Protocol Buffers - A method for serializing and interchanging structured data.