samples/toolWindow/src/META-INF/plugin.xml

<idea-plugin version="2">
  <name>Tool Window</name>
  <description>This sample plugin illustrates how to create your custom tool window.</description>
  <version>1.0</version>
  <vendor>JetBrains</vendor>
    <!--
    <idea-version since-build="8000"/>
    -->
  <application-components>
    <!-- Add your application components here -->
  </application-components>

  <project-components>
    <!-- Add your project components here -->
     
  </project-components>

  <actions>
    <!-- Add your actions here -->
  </actions>

  <extensions defaultExtensionNs="com.intellij">
    <!-- Add your extensions here -->                       
     <toolWindow id="Sample Calendar"   secondary="true" icon="/general/add.png" anchor="right" factoryClass="myToolWindow.MyToolWindowFactory"   >
         
     </toolWindow>
  </extensions>
</idea-plugin>