[dredmorbius]

The syntax (and theory behind it) are really arcane, but jq is phenomenally powerful.

For websites which can publish JSON extracts, piping that through jq to get just what you want and how you want it is an absolute lifesaver.

[wwader]

Yeap the syntax and semantics is quite different to other languages and it really took me a long time and deep understanding to really appreciate how expressive and damn well designed it is.