A pre-process is done before the main transformation. The input of the pre-process is dita files (maps and topics) and the output of the pre-process is often referred to as "normalized" dita files. The pre-process stage resolves several common DITA behaviors, such as resolving conref attributes, resolving keyref values, and adding links based on the hierarchy and relationship tables in a map. The normalized dita files are in a temporary directory. Most DITA transforms use this common pre-process setup.

A core DITA transform is the basic set of templates that support all the elements of a topic. This set is the basis for the following processing of any specialized element. Core transforms handle one topic instance, or nested set of topics, at a time. The DITA Open Toolkit provides several core transforms:

PDF

PDF output is based on a plug-in that produces XSL-FO output. The XSL-FO output may be converted to PDF using an open source tools (Apache FOP) or using commercial tools such as RenderX or Antenna House Formatter. This transformation type replaced an older demo PDF transform, and is often called "PDF2".

XHTML

XHTML output is supported together with a variety of XHTML-based navigation types. Navigation is not required. The XHTML output contains class values based on the DITA elements so CSS files may be used to customize the output style.

Eclipse Help

Eclipse output is an XHTML based format that also produces navigation and index files for use with Eclipse information centers.

TocJS

The TocJS transformation type includes XHTML output along with JavaScript based frames for navigation, including TOC sections that expand and collapse.

HTML Help

Microsoft Compiled HTML Help output produces a compiled help (.chm) file with the XHTML topics, table of contents, and index.

Java Help

Java Help includes a table of contents and index for use with the Java Help platform.

OpenDocument (ODT)

ODT is a document format based on the ODF standard, for use with tools like Open Office. Support for ODT was added in DITA-OT 1.5.2.

Rich Text Format (RTF)

RTF output is supported for basic content, but complex markup and some advanced features of DITA may not be supported.

troff

troff based man pages are supported; one man page is generated for each input topic. Note that tables are not supported by this transformation type.

The complete transformation including pre-process can be executed by an Ant script. There are some examples of simple Ant scripts in the directory samples/ant_sample.