JSONFormatter.org - Online JSON Formatter and JSON Validator will format JSON data, and helps to validate, convert JSON to XML, JSON to CSV. Save and Share JSON

FreeFormatter - Freeformatter is a platform that contains free online tools for developers, including formatters (json, html, xml, sql, etc.), minifiers (css, javascript), compactors, validators, and much more.

Oxygen XML Editor - Oxygen XML Editor provides a comprehensive suite of XML authoring and development tools.

Google web toolkit - Google web toolkit is a development tool mostly used by world-class developers for building and optimizing complex browser-based applications.

Easy XML Editor Pro - XML-Editor for comfortable editing of XML, with many helpers for productive working

Wt - Wt (pronounced as witty) is a C++ library for developing web applications.