	<taskdef name="rulebase" classname="org.drools.contrib.DroolsCompilerAntTask" classpathref="drools.classpath" />


And use the rulebase task as the following example

	<target name="rules" >
		<rulebase 
			srcdir="${eclipsepath}src/test/resources/rules" 		
			tofile="${eclipsepath}target/cheese.rules"

			classpathref="cheese.classpath" > 
			<include name="*.drl" />
			<include name="*.brl" />
			<include name="*.xml" />
			<include name="*.dslr" />			

		</rulebase>
	</target>
	

you can see my test XML file here http://anonsvn.labs.jboss.com/labs/jbossrules/trunk/drools-ant/src/test/resources/DroolsAntTask.xml