title: Is effective-pom a merge between super pom and application POM
body: <p>I have tried to generate effective pom on sample application using mvn help:effective-pom command. 
  <a href="http://books.sonatype.com/mvnref-book/reference/pom-relationships-sect-pom.html" rel="noreferrer">http://books.sonatype.com/mvnref-book/reference/pom-relationships-sect-pom.html</a>
  at this article it says effective pom is a merge between super pom and application pom. </p>
  
  <p>But, When I look at my effective-pom, it contains elements which are not included in the either super pom or effective pom. </p>
  
  <p>Is there other factor deciding what goes into effective pom. </p>
  
  <p>Given below is the super pom and application pom, Both of these pom's does not have mavne-jar-plugin or maven-compiler-plugin, but in my effective-pom , I can see those plugins in the build section. So how does it get added. </p>
  
  <p>Thanks in advance for any help on clarifying this issue </p>
  
  <p>Super POM</p>
  
  <pre><code>&lt;!--
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  to you under the Apache License, Version 2.0 (the
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  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  KIND, either express or implied.  See the License for the
  specific language governing permissions and limitations
  under the License.
  --&gt;
  
  &lt;!-- START SNIPPET: superpom --&gt;
  &lt;project&gt;
    &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
  
    &lt;repositories&gt;
      &lt;repository&gt;
        &lt;id&gt;central&lt;/id&gt;
        &lt;name&gt;Central Repository&lt;/name&gt;
        &lt;url&gt;http://repo.maven.apache.org/maven2&lt;/url&gt;
        &lt;layout&gt;default&lt;/layout&gt;
        &lt;snapshots&gt;
          &lt;enabled&gt;false&lt;/enabled&gt;
        &lt;/snapshots&gt;
      &lt;/repository&gt;
    &lt;/repositories&gt;
  
    &lt;pluginRepositories&gt;
      &lt;pluginRepository&gt;
        &lt;id&gt;central&lt;/id&gt;
        &lt;name&gt;Central Repository&lt;/name&gt;
        &lt;url&gt;http://repo.maven.apache.org/maven2&lt;/url&gt;
        &lt;layout&gt;default&lt;/layout&gt;
        &lt;snapshots&gt;
          &lt;enabled&gt;false&lt;/enabled&gt;
        &lt;/snapshots&gt;
        &lt;releases&gt;
          &lt;updatePolicy&gt;never&lt;/updatePolicy&gt;
        &lt;/releases&gt;
      &lt;/pluginRepository&gt;
    &lt;/pluginRepositories&gt;
  
    &lt;build&gt;
      &lt;directory&gt;${project.basedir}/target&lt;/directory&gt;
      &lt;outputDirectory&gt;${project.build.directory}/classes&lt;/outputDirectory&gt;
      &lt;finalName&gt;${project.artifactId}-${project.version}&lt;/finalName&gt;
      &lt;testOutputDirectory&gt;${project.build.directory}/test-classes&lt;/testOutputDirectory&gt;
      &lt;sourceDirectory&gt;${project.basedir}/src/main/java&lt;/sourceDirectory&gt;
      &lt;scriptSourceDirectory&gt;src/main/scripts&lt;/scriptSourceDirectory&gt;
      &lt;testSourceDirectory&gt;${project.basedir}/src/test/java&lt;/testSourceDirectory&gt;
      &lt;resources&gt;
        &lt;resource&gt;
          &lt;directory&gt;${project.basedir}/src/main/resources&lt;/directory&gt;
        &lt;/resource&gt;
      &lt;/resources&gt;
      &lt;testResources&gt;
        &lt;testResource&gt;
          &lt;directory&gt;${project.basedir}/src/test/resources&lt;/directory&gt;
        &lt;/testResource&gt;
      &lt;/testResources&gt;
      &lt;pluginManagement&gt;
        &lt;!-- NOTE: These plugins will be removed from future versions of the super POM --&gt;
        &lt;!-- They are kept for the moment as they are very unlikely to conflict with lifecycle mappings (MNG-4453) --&gt;
        &lt;plugins&gt;
          &lt;plugin&gt;
            &lt;artifactId&gt;maven-antrun-plugin&lt;/artifactId&gt;
            &lt;version&gt;1.3&lt;/version&gt;
          &lt;/plugin&gt;
          &lt;plugin&gt;
            &lt;artifactId&gt;maven-assembly-plugin&lt;/artifactId&gt;
            &lt;version&gt;2.2-beta-5&lt;/version&gt;
          &lt;/plugin&gt;
          &lt;plugin&gt;
            &lt;artifactId&gt;maven-dependency-plugin&lt;/artifactId&gt;
            &lt;version&gt;2.1&lt;/version&gt;
          &lt;/plugin&gt;
          &lt;plugin&gt;
            &lt;artifactId&gt;maven-release-plugin&lt;/artifactId&gt;
            &lt;version&gt;2.0&lt;/version&gt;
          &lt;/plugin&gt;
        &lt;/plugins&gt;
      &lt;/pluginManagement&gt;
    &lt;/build&gt;
  
    &lt;reporting&gt;
      &lt;outputDirectory&gt;${project.build.directory}/site&lt;/outputDirectory&gt;
    &lt;/reporting&gt;
  
    &lt;profiles&gt;
      &lt;!-- NOTE: The release profile will be removed from future versions of the super POM --&gt;
      &lt;profile&gt;
        &lt;id&gt;release-profile&lt;/id&gt;
  
        &lt;activation&gt;
          &lt;property&gt;
            &lt;name&gt;performRelease&lt;/name&gt;
            &lt;value&gt;true&lt;/value&gt;
          &lt;/property&gt;
        &lt;/activation&gt;
  
        &lt;build&gt;
          &lt;plugins&gt;
            &lt;plugin&gt;
              &lt;inherited&gt;true&lt;/inherited&gt;
              &lt;artifactId&gt;maven-source-plugin&lt;/artifactId&gt;
              &lt;executions&gt;
                &lt;execution&gt;
                  &lt;id&gt;attach-sources&lt;/id&gt;
                  &lt;goals&gt;
                    &lt;goal&gt;jar&lt;/goal&gt;
                  &lt;/goals&gt;
                &lt;/execution&gt;
              &lt;/executions&gt;
            &lt;/plugin&gt;
            &lt;plugin&gt;
              &lt;inherited&gt;true&lt;/inherited&gt;
              &lt;artifactId&gt;maven-javadoc-plugin&lt;/artifactId&gt;
              &lt;executions&gt;
                &lt;execution&gt;
                  &lt;id&gt;attach-javadocs&lt;/id&gt;
                  &lt;goals&gt;
                    &lt;goal&gt;jar&lt;/goal&gt;
                  &lt;/goals&gt;
                &lt;/execution&gt;
              &lt;/executions&gt;
            &lt;/plugin&gt;
            &lt;plugin&gt;
              &lt;inherited&gt;true&lt;/inherited&gt;
              &lt;artifactId&gt;maven-deploy-plugin&lt;/artifactId&gt;
              &lt;configuration&gt;
                &lt;updateReleaseInfo&gt;true&lt;/updateReleaseInfo&gt;
              &lt;/configuration&gt;
            &lt;/plugin&gt;
          &lt;/plugins&gt;
        &lt;/build&gt;
      &lt;/profile&gt;
    &lt;/profiles&gt;
  
  &lt;/project&gt;
  &lt;!-- END SNIPPET: superpom --&gt;
  </code></pre>
  
  <p>Application POM</p>
  
  <pre><code>&lt;project&gt;
      &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
      &lt;groupId&gt;org.sonatype.mavenbook.ch08&lt;/groupId&gt;
      &lt;artifactId&gt;simplest-project&lt;/artifactId&gt;
      &lt;packaging&gt;jar&lt;/packaging&gt;
      &lt;version&gt;1&lt;/version&gt;
  &lt;/project&gt;
  </code></pre>
  
  <p>effective pom</p>