JSON6 is a JavaScript library that implements a superset of JSON, adding human‑friendly ES6‑style syntax such as comments, unquoted keys, back‑tick and single‑quoted strings, trailing commas, numeric separators, binary/octal/hex literals, and the `undefined` keyword. It provides a drop‑in `JSON6` object (with `parse`, `stringify`, streaming and require‑hook support) for Node.js and browsers, targeting developers who write configuration, manifest or test files by hand and want the convenience of JavaScript‑like syntax without leaving the JSON ecosystem.