YAML in Perl

YAML: YAML Ain't Markup Language is a text format that provides hierarchical data structures similar to JSON, but it is especially human readable.

examples/sample.yml

---
YAML: YAML Ain't Markup Language
Languages:
  - perl
  - python
  - javascript

It can be used for data serialization, though probbaly it is most often used for hierarchical configuration files.

YAML format allows the user to have key-value pair and list data structures.

Plenty of languages have YAML reader and write libraries.