Third-party software DITA Open Toolkit uses third-party software components to provide certain features in the core toolkit, Java API, and bundled plug-ins.
DITA-OT <keyword keyref="release"/>

DITA-OT core processing uses the following third-party software:

Software Version License Ant Apache Commons Codec Apache Commons IO Guava ICU for Java (ICU4J) Logback Classic Module , Simple Logging Facade for Java (SLF4J) Xerces XML APIs , XML Resolver
The XML APIs library contains source code for SAX and DOM APIs, which each have their own licenses.
PDF plug-in

The org.dita.pdf2 plug-in relies on additional third-party software to generate PDF output:

Software Version License Apache Commons Logging 1.0.4 Avalon Framework 4.3.1 Apache XML Graphics 2.1 Batik 1.8 FOP