oXygen XML Editor combines an easy to use visual editor with a powerful code based editor thus covering the needs of both authors that do not want to see the tags and XML gurus that want to have full control over their markup.  

DITA support comes built in consisting of

XMLmind XML Editor allows to edit large, complex, modular, XML documents. It makes it easy mastering XML vocabularies such as DocBook or DITA. (More info.)

As you can see it in the screen shot below, XMLmind XML Editor is not a tool for programmers. Its users are generally technical writers.

oXygen is a cross-platform XML Editor. Besides the top-of-the-line XML source editing support, it features a CSS driven WYSIWYG XML editing mode allowing the content authors to visually edit DITA documents. oXygen features include out-of-the-box integration with the DITA Open Toolkit and can be easily customized to match your DITA editing and publishing needs.

This utility parses all the DITA files referenced in a ditamap file (including all conrefs in any file) and gives a list of all conditional attribute values found in product, platform, audience and otherprops. Using this list, you can check that all the values are valid and that there are no mistaken values. You can then choose which attributes to include and exclude, and automatically generate a ditaval file.

Developed and supported by Suite Solutions.

Download the Ditaval File Generation Utility

DITA Storm™ Developer (www.inmediusdita.com) is a full-featured DITA editing tool that enables authors to easily create DITA-compliant content in WYSIWYG mode regardless of their DITA or XML knowledge.  The editing environment is 100% browser-based, requiring no timely or costly client installations or updates, and is completely customizable for a superior DITA user experience.  Non-technical authors create structured content in a familiar environment while ensuring that the entire DITA documentation lifecycle is supported through easy integration into an exiting CMS.