Here is a list some of the XML editors:
1) Stylus Studio 6 (Commercial) 2) Conglomerate (OpenSource) 3) XMetal (Commercial) 4) JEdit (OpenSource) 6) Timelux Xpress 7) Excosoft XML Client 8) Xeena by IBM (commercial) 9) XML Editor - Java based (commercial) 10) Markup Editor 1.1.3 by topologi (commercial) 11) EditML Pro by NETBRYX 12) ElfData XML Editor 13) lucid' xml editor 14) XMLware 15) XML Pro by Vervet Logic 16) xml origin 17) xmloperator 18) Exchanger XML Editor 19) xmlBlueprint XML Editor 20) Visual SlickEdit 21) epcE
WYSIWYG XML Editors 1) EditiX (Commercial) 2) Authentic by Altova (Commercial) 3) XMLEditor by XMLMind (Commercial) 4) i4i Tagless Editor (Commercial) 5) XMLWriter by Wattle Software (Commercial) 6) eWebEditPro+XML 3.1 by Extron 7) Ultra XML by webxsystems 8) Morphon (Commercial) 9) XMLSpy by Altova 10) Web-based XML editor 11) Syntext Serna (based on XSL-FO) (Win/Lin/Mac) 12) Vex - A Visual Editor for XML 13) Xopus Browser-based WYSIWYG XML editor (XSL+HTML+CSS+JS, XSD) (Commercial)