[mintplant]

TOML.

https://github.com/toml-lang/toml

[brandonbloom]

I (original commenter) second TOML. It is very simple, is instantly familiar to anyone who has used ini files or many Unix-style config files, and has many good implementations available.

The [[array]] notation mentioned below is a tad weird, but I've never had an occasion to use it.

[nikolay]

[[ something ]]? No, thank you! Jsonnet [0], yes, please!

[0]: http://jsonnet.org/

[placeybordeaux]

Why?

[nikolay]

It's just weird syntax in my view.