Prerequisite software

The prerequisite software that DITA-OT requires depends on the types of transformations that you want to use.

Software required for core DITA-OT processing

DITA-OT requires the following software applications:

Java Runtime Environment (JRE) or Java Development Kit (JDK)

DITA-OT is designed to run on Java version 8u101 or later and built and tested with the Open Java Development Kit (OpenJDK). Compatible Java distributions are available from multiple sources:

You can download the Oracle JRE or JDK from oracle.com/technetwork/java under commercial license.
OpenJDK is a free open-source implementation of Java available from adoptopenjdk.net.
Free OpenJDK distributions are also available from other vendors, including Amazon Corretto, Azul Zulu, and Red Hat.

Note: This is the only prerequisite software that you need to install. The remaining required software is included in the distribution package.

Apache Ant

Provides the standard setup and sequencing of processing steps. DITA-OT includes Ant version 1.10.9. You can download Ant from ant.apache.org.

XSLT processor

Provides the main transformation services. It must be compliant with XSLT 2.0. DITA-OT includes Saxon version 9.9.1.4. You can download Saxon from saxon.sourceforge.net.

Software required for specific transformations

Depending on the type of output that you want to generate, you might need the following applications:

ICU for Java: ICU for Java is a cross-platform, Unicode-based, globalization library. It includes support for comparing locale-sensitive strings; formatting dates, times, numbers, currencies, and messages; detecting text boundaries; and converting character sets. You can download ICU for Java from icu-project.org/download.
Microsoft Help Workshop: Required for generating HTML help. You can download the Help Workshop from msdn.microsoft.com.
XSL-FO processor: Required for generating PDF output. Apache™ FOP (Formatting Objects Processor) is included in the distribution package. You can download other versions from xmlgraphics.apache.org/fop. You can also use commercial FO processors such as Antenna House Formatter or RenderX XEP.