SCHEMA ST4 is a standard software application which you can use to create, organize and produce product information efficiently and securely. SCHEMA ST4 covers the full range of requirements and manages pre-sales information such as catalogs, as well as post-sales documents such as product documentation, training documents and contract texts.

DitaShare by Content Technologies GmbH is a DITA-based Single-Source CMS solution on Microsoft Office SharePoint Server 2007 that offers collaborative Single-Sourcing and re-use of DITA topics and DITA maps, as well as publishing of conditional variants. DitaShare includes an integrated version of Altova Authentic 2008, a free web-based XML content editor, allowing authors and editors to work productively from any location using only MS Internet Explorer. Optional web-based editors include JustSystems XMAX, Xopus, and DITA Storm.

The ability to manage enterprise content today is more important than ever. Documents, web sites, technical publications and portals - your business needs a system to keep content under control, re-use it across departments and monetize it across multiple distribution channels. With SR2, Refresh Software is shaping the future of Component Content Management for web sites and documents.

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.