DITA OT processing pipeline

The DITA Open Toolkit implements a multi-stage, map-driven architecture to process DITA content. Each step in the process examines some or all of the content; some steps result in temporary files used by later steps, while others result in updated copies of the DITA content. Most of the processing takes place in a temporary working directory (the source files themselves are never modified).

Transformations in the toolkit are designed like a pipeline. Most of the pipeline is common between all output formats, and is known as the preprocess stage. In general, any DITA process begins with this common set of preprocessing routines. Once the preprocessing is completed, the pipeline diverges based on the desired output format. Some processing is still common to multiple output formats; for example, Eclipse Help and HTML Help both use the same routines to generate XHTML topics, after which the two pipelines branch to create a different set of navigation files.

The following image illustrates how the pipeline works for some common output types.