Before installing DITA Open Toolkit and its prerequisite software on Mac OS X, check to see if any of the tools are already installed on your system and, if so, whether the version you have is supported (see System requirements and supported applications).). Java is a core component of Mac OS X. Newer versions of Mac OS X include the full version of the Java JDK 1.4.2 by default. This version of the JDK includes Ant and the Xalan-J XSLT processor, as well. Other tools you want to install may be included on the Mac OS X Developer's Tools on the product DVD.
To install the Toolkit, extract the zip file to your HOME directory, then edit your login rc file to include the Toolkit in your CLASSPATH.