plugin.xml

<?xml version="1.0" encoding="UTF-8"?>
<?eclipse version="3.0"?>
<plugin>

   <!-- This is an example for providing an own category 
      <extension
         point="org.knime.workbench.repository.categories">
      <category
            description="Category containing my nodes"
            icon="icons/default.png"
            level-id="myNodes"
            name="My nodes"
            path="/"/>
   </extension>
   -->
   
   <extension
         point="org.knime.workbench.repository.nodes">
      <node
            category-path="/"
            factory-class="org.bof.HistogrammCreatorNodeFactory"
            id="org.bof.HistogrammCreatorNodeFactory"/>
   </extension>
   <extension
         point="org.knime.workbench.repository.nodesets">
      <nodeset
            default-category-icon="/icons/default.png"
            expert-flag="false"
            factory-class="org.bof.geometric.DescriptorNodeSetFactory"
            id="org.bof.geometric.DescriptorNodeSetFactory">
      </nodeset>
   </extension>
   
</plugin>