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. Using the stock
'gcc-java' package, by exporting JAVA_HOME=/usr/lib{64}/jvm envirnoment
variable. Or from slackbuilds.org, one of jdk, openjdk* works just fine.