pom.xml

  <dependency>
    <groupId>org.jruby</groupId>
    <artifactId>jruby-complete</artifactId>
    <version>1.3.1</version>
    <scope>provided</scope>
  </dependency>

  <properties>
    <jruby>${settings.localRepository}/org/jruby/jruby-complete/1.3.1/jruby-complete-1.3.1.jar</jruby>
  </properties>

  <artifactId>maven-antrun-plugin</artifactId>
  <executions>
    <execution>
      <id>my_script</id>
      <phase>compile</phase>
      <configuration>
        <tasks>
          <java jar="${jruby}" fork="true" failonerror="yes">
            <arg value="${basedir}/src/main/ruby/myscript.rb" />
          </java>
        </tasks>
      </configuration>
    </execution>
  </executions>