XMLQuire (Vista/7) for Windows

This simple-to-use and free XML Editor brings a new editing experience: XML indentation is fully automated and entirely separate from XML content -no formatting tabs or spaces. Double-clicking on the XPath-Location bar will launch the integrated XPath Editor, featuring full auto-completion and a unique 'predicate-by-predicate' trace capability.

Feature include:Syntax-highlighting and auto-completion, Schema validation and schema-aware completion lists, DTD caching, Regex powered Find and Replace with preview, Special Print Preview with XML print formatting options, Recent Files list with preserved state replaces document tabs, Element cursor provides quick mouse-selection of an complete element, Virtual Formatting means reformatting of XML is continuous, as you type, All whitespace content preserved - What You Type Is What You Get (WYTIWYG), Seamless drag and drop where formatting reflows automatically, and Optional permanent auto-complete list for inline markup.