Data Studio

XML becomes objects with each attribute as “@name” and an element’s text as “#text”; an element that repeats becomes a list, and it’s written back the same way.
CSV’s first row names the columns; its separator is found from that row. Every value stays text, as CSV has no numbers.
ENV names with __ nest, as .NET reads them (Logging__LogLevel__Default), and written ENV nests the same way. INI’s [a.b] nests too. Both hold only text.
The Table shows the list picked in the Tree, else the first list of objects. JSONPath runs with a safe evaluator, never eval; XPath reads XML with your browser’s own, and both light their matches in the tree.
Beautify and Minify write the box out again in its own format; Sort keys puts every object’s names in order. Ctrl+Z takes either back.
YAML is read and written with yaml (ISC) and JSONPath with jsonpath-plus (MIT), both kept on this site.