This topic describes the role XSL-T processors play in the DITA Open Toolkit.
For DITA content to be transformed from its XML-based authoring format to one of many reading formats, the content files must be processed through an XSL-T processor. XSL-T stands for XML Stylesheet Language - Transformations, and is an extremely useful and widely used XML technology. An XSL-T processor applies the transformation rules in an XSL-T file to an XML data document to produce an output document.
The DITA Open Toolkit can work with two popular XSL-T processors: Xalan and Saxon. If you don't already one of those processors installed, it's easiest to choose Xalan, because it actually gets installed with the full package DITA Open Toolkit, into the folder [DITA_OT_DIR]\lib\.
Note: If you choose to use Saxon as your DITA OT XSL-T processor, or you have Xalan installed in a different location to the DITA OT installation, you must add the XSL-T processor location to your CLASSPATH environment variable. Refer to the DITA Open Toolkit User Guide for instructions for setting the CLASSPATH.