JSON isn't the friendliest to write and maintain by hand. Keys need to be quoted; objects and arrays can't have trailing commas; comments aren't supported — even though none of these are the case with regular JavaScript today. JSON5 is a proposed extension to JSON that brings ES5 enhancements to its syntax. It remains a strict subset of JavaScript, adds no new data types, and is a strict superset of existing JSON. - dexter.yy