Darryl K. Taft  – eweek: “Google recently introduced a new open-source configuration language for generating JSON known as Jsonnet. Google quietly released Jsonnet a few months ago as a programming language for specifying data. The Jsonnet Website calls Jsonnet a data templating language. Jsonnet doesn’t just generate JSON: It is also an extension of JSON, said Dave Cunningham, a member of Google’s New York Technical Infrastructure team, in a blog post about the new language. “By adding new constructs between the gaps of existing JSON syntax, Jsonnet adds useful features without breaking backwards compatibility,” Cunningham said. “Any valid JSON is also a valid Jsonnet program that simply emits that JSON unchanged, and existing systems that consume JSON (or its cousin YAML) can be easily modified to accept data in the full Jsonnet language. As such, Jsonnet is an example of a templating language, but one specifically designed for JSON data and less error-prone than other techniques.”Cunningham also noted that many systems can be configured with JSON, but writing it by hand can be difficult. “Jsonnet is packed with useful data-specification features that expand into JSON for other systems to act upon,” he said. JSON, or JavaScript Object Notation, is an open standard format that uses human-readable text to transmit data objects consisting of attribute-value pairs. It is used primarily to transmit data between a server and Web application, as an alternative to XML.”