Apache Ant is a Java-based build tool - like make, but without make's
wrinkles. :-)

Ant is extended using Java classes. The configuration files are XML-based,
calling out a target tree where tasks get executed. Each task is run by an
object that implements a Task interface.

This package is using upstream's recommendation of ANT_HOME=/usr/share/ant

apache-ant uses `javac` and friends to compile java projects.
If you use the stock 'gcc-java' package, then you will need to export the
JAVA_HOME environment variable, and make it point to the Java5 run-time
provided by the GNU Compiler Collection, e.g.:

   export JAVA_HOME=/usr/lib/jvm        (for Slackware, 32-bit)

or:

   export JAVA_HOME=/usr/lib64/jvm      (for Slackware64)

If you need a more recent Java run-time, then any of the jdk or openjdk
packages from slackbuilds.org will work just fine.