JSON syntax is a subset of YAML version 1.2

JSON (JavaScript Object Notation) is a lightweight data-interchange format. It is easy for humans to read and write. It is easy for machines to parse and generate. It is based on a subset of the JavaScript Programming Language, Standard ECMA-262 3rd Edition - December 1999. JSON is a text format that is completely language independent but uses conventions that are familiar to programmers of the C-family of languages, including C, C++, C#, Java, JavaScript, Perl, Python, and many others. These properties make JSON an ideal data-interchange language.

from http://www.json.org/

javascript에서 기본적으로 인식되고 java나 basic, c, python 등 다양한 언어에서 지원 라이브러리가 존재한다.