The DITA Open Toolkit is a collection of tools, sample DITA files, schema files, and documentation. The following DITA Open Toolkit tools are used within the publishing process:

• XSL-T Transformation Engine
• Build Tool
• XML Parser
• XSL-FO Rendering Engine

Most tools in the Toolkit are Java-based, so you must have the Java development environment installed before installing the Toolkit. The Java environment required is known as the JDK.

The Toolkit includes the Xalan XSL-T transformation engine. However, you can also use Saxon, but you must download and install this separately. The role of the transformation engine is to convert DITA content to other forms of XML, including XHTML, DocBook and XSL-FO. If Saxon is specified in the classpath, Saxon will be used; otherwise Xalan will be used.

The Toolkit includes the Apache Ant built tool. This tool controls the setup and sequence of the publishing process, which usually includes a number of coordinated steps. For example, when DITA content is transformed to PDF, it must first be flattened (conrefs resolved), then transformed to XSL-FO, and then the XSL-FO processed to PDF. (The process is actually more complicated, but this simplified example illustrates the point.)

The toolkit includes the Xerces XML Parser. Xerces is used by XSLT processors.

The Toolkit includes the Apache FOP XSL-FO rendering engine. However, you can also use the RenderX XEP rending engine, but you must download and install this separately. To use the XEP rendering engine, you must also download an install an extension (the FO plugin) to the DITA Open Toolkit. The rendering engine transforms the XSL-FO content generated from the DITA source to PDF output format.

If you need to build compiled Help such as JavaHelp and HTML Help, you must also download and install the JHH (for JavaHelp) and HHW (for HTML Help) compilers.

You can use WinANT's diagnostic feature to identify which versions of which DITA OT tools you have installed. From the Help menu, choose Diagnostics....