org.eclipse.jdt.launching/scripts/buildLaunchingSupportJAR.xml

<?xml version="1.0" encoding="UTF-8"?>
<project name="Build Launching Support JAR" default="build" basedir="..">

	<target name="build" description="Cleans, builds and refreshes">
		<antcall target="clean"/>
		<antcall target="lib/launchingsupport.jar"/>
	</target>

	<target name="init" depends="properties">
		<property name="bootclasspath" value=""/>
		<property name="temp.folder" value="${basedir}/temp.folder"/>
		<property name="build.result.folder" value="${basedir}"/>
	</target>

	<target name="properties" if="eclipse.running">
		<property name="build.compiler" value="org.eclipse.jdt.core.JDTCompilerAdapter"/>
	</target>
	
	<target name="lib/launchingsupport.jar" description= "Creates the launchingsupport.jar" depends="init">
		<property name="destdir" value="${temp.folder}/lib/launchingsupport.jar.bin"/>
		<delete dir="${temp.folder}/lib/launchingsupport.jar.bin"/>
		<mkdir dir="${temp.folder}/lib/launchingsupport.jar.bin"/>
		<!-- compile the source code -->
		<javac target="1.2" source="1.3" destdir="${temp.folder}/lib/launchingsupport.jar.bin" failonerror="false" verbose="false" debug="on" includeJavaRuntime= "yes" includeAntRuntime="no"
			 bootclasspath="${bootclasspath}" classpath="">
			<src path="support/"/>
		</javac>
		<mkdir dir="${build.result.folder}/lib"/>
		<jar jarfile="${build.result.folder}/lib/launchingsupport.jar" basedir="${temp.folder}/lib/launchingsupport.jar.bin"/>
		<delete dir="${temp.folder}"/>
	</target>

	<target name="clean" description="Deletes previous build remnants" depends="init">
		<delete file="${build.result.folder}/lib/launchingsupport.jar"/>
		<delete dir="${temp.folder}"/>
	</target>
</project>