If you want to go GUI, then look at XMLmind FO Converter (XFC), which combines an XSL processor and an XSL-FO processor in a point-and-click package. To create PDF, PostScript, or RTF files, first run your document through an XSL processor and then through an XSL Formatting Objects (XSL-FO) processor such as the free Formatting Objects Processor (FOP) or the commercial RenderX XEP Engine. For most formats, you can use an XSL processor such as the popular Saxon or xsltproc. The stylesheet determines the output format, and the XSL processor does the grunt work. You produce output in DocBook by applying XSL stylesheets to your files using an XSL processor. Vex, an XML editor based on Eclipse, is an excellent DocBook editor, as is XMLmind XML Editor (XXE), a WYSIWYG editor written in Java. A tutorial explains how to use Vim as a DocBook editor. Others use Vim, along with a script or two. Some writers use Emacs with the psgmlx or nXML packages. Since DocBook files are XML, you can edit them in any XML or text editor. This enables you to maintain all of your information in one file rather than in multiple documents. You can also author multiple documents that contain much of the same content, but which are intended for different users or different operating systems. You can use DocBook to output documentation in multiple formats, including PDF and PostScript (for printing), HTML, HTML Help, and JavaHelp. It’s a variant of XML designed specifically for authoring software and hardware manuals. The DocBook Project isn’t an application, but it is arguably the biggest gun in the Linux technical writing arsenal. All of them give technical writers the ability to author and publish professional documentation. Linux users can take advantage of a number of documentation tools, including both free or open source software (FOSS) and proprietary software. While Linux lacks standard Windows tools such as FrameMaker, RoboHelp, and WebWorks Publisher, it’s still a viable environment for technical writers. Documentation is a necessary evil of software development.

Help documentation software