Syntext Serna Free is an easy-to-use yet powerful solution for WYSIWYG XML authoring. Serna Free is intended for personal use at home, documenting open-source projects, education, and other non-commercial uses. Authors with virtually no XML experience can start working with structured content in a familiar environment that looks much like a conventional word processor.
Serna employs XSLT and XSL-FO to render documents in print-like appearance. This approach gives a lot of opportunities for document rendering, such as localized generated content, profiled views, composition of a document from multiple chunks, in-line attribute editing, and others.

Serna offers exceptional DITA 1.1 support and comes with integrated DITA Open Toolkit. Flexible visualization of DITA maps and topics with the ability to resolve referred content and in-place editing of local conrefs greatly simplify DITA authoring.

Features
Available for Microsoft Windows™ (2000, XP, Vista), Linux, Mac OS X, and Sun Solaris/SPARC
Built-in support for all popular document types (DITA, Docbook, XHTML, TEI P4, NITF, etc)
On-the-fly document validation against XML Schemas
Context-sensitive element help
Entity and XInclude in-place editing
Drag-and-drop with on-the-fly validation
UNICODE support and multilingual spell checking
User interface localized into several languages (including Chinese, Dutch, French, German, Igbo, Italian, Norwegian, Russian, Swedish)

Free registration is required with the developer