HEATKEYS

Online tools for developers, including formatters (JSON, XML, HTML, SQL, etc.), minifiers (JavaScript, CSS), validators, compactors and many more!

A web-based XML validator. Can be used for free. Validates XML files, prompts the user for referenced files (e. g., XSD), shows good error messages.

The Microsoft Support home page is your support portal for Microsoft products. Download updates and find top issues, error messages, and troubleshooting tips for Windows XP, Windows Vista, Windows 7, Office 2010, the 2007 Microsoft Office system, and...

XMLFox XML/XSD editor is the Windows based graphical tool for authoring, updating, exploring, well-formedness checking or validating XML documents. XMLFox is a graphical XML editing and validation tool for creating valid, well-formed XML documents an...

Free cross-platform web-based Online XML Editor, runs on Linux, Windows, Mac, FireFox, Chrome, IE. Edit XML schema or document. No user registration required.

Groovy Wiki

The World Wide Web Consortium (W3C) is an international community where Member organizations, a full-time staff, and the public work together to develop Web standards.

Altova XMLSpy XML editor, plus other leading XML, data management, UML, and Web services software tools for application, web site, and database development, data conversion, and more.

XMLBlueprint is a lightweight XML editor that supports XML documents, DTDs, Relax NG Schemas and XML Schemas. It supports XSLT transformations, Unicode.

oXygen XML Editor is a cross platform XML Editor providing tools for XML authoring, XML conversion, XSL, XSLT, XQuery, XML Schema, DTD, Relax NG and Schematron development, SOAP and WSDL.