JSONLint - JSON Lint is a web based validator and reformatter for JSON, a lightweight data-interchange format.
ClangFormat - A tool to format C/C++/Java/JavaScript/Objective-C/Protobuf code.
JSON Formatter & Validator - The JSON Formatter was created to help with debugging.
Uncrustify - Banish crusty code with the Uncrustify C/C++/C#/Obj-C/D/Java/Pawn/VALA source code beautifier.
JSON Editor Online - View, edit and format JSON online
Artistic Style - astyle, code formatting