I've posted the notes from this morning's RELAX NG session, one of two new classes I'm giving this year at Software Development 2005 West, The talk went well, though there's still a lot of skepticism (which I hope I ameliorated) about whether anything other than the W3C XML Schema Language has a chance. Tool support was a particular concern.
JAPISoft has released EditiX 3.1, a $92 payware XML editor written in Java. Features include XPath location and syntax error detection, context sensitive popups based on DTD, W3C XML Schema Language, and RelaxNG schemas, XSLT and XSL-FO previews, XInclude. XML catalogs, an XSLT debugger, DocBook support, and multi-view preview. Version 3.1 adds a file browser. EditiX is available for Mac OS X, Linux, and Windows. Upgrades from 1.x are $59.