Packaging your configuration for XXE add-on manager is optional. However, if you deploy XXE as a desktop application, this packaging allows your users to easily install, upgrade or uninstall your configuration using menu item Options → Install Add-ons.

An add-on is simply a Zip archive ("zip" file extension) where all the files and directories comprising the add-on are contained in a single topmost directory. Among these files, XXE must find a single file having a "xxe_addon" extension. For example, let's suppose the configuration based on the XML schema is found in xsd_section_config.zip. Unzipping this file would give:

C:\> unzip xsd_section_config.zip
   creating: xsd_section_config/
  inflating: xsd_section_config/common.incl
  inflating: xsd_section_config/section.xsd
  ...
  inflating: xsd_section_config/xsd_section_config.xxe_addon
  ...
  inflating: xsd_section_config/catalog.xml

File xsd_section_config.xxe_addon contains:

<a:addon xmlns="http://www.w3.org/1999/xhtml"
         xmlns:html="http://www.w3.org/1999/xhtml"
         xmlns:a="http://www.xmlmind.com/xmleditor/schema/addon">
  <a:category>
    <a:configuration />
  </a:category>

  <a:name>"Simple Section (XML Schema)" Configuration</a:name>

  <a:version>1.0.0</a:version>

  <a:abstract>Part of the tutorial explaining how to write a configuration for
  XMLmind XML Editor.</a:abstract>
</a:addon>

The easiest way to create an .xxe_addon file is to use XXE:

Make sure to carefully choose a unique, descriptive, stable name for your add-on. Changing the name of an add-on from one release to another is likely to annoy your users. For example, this breaks the upgrade facility offered by XXE add-on manager.

More information in "XMLmind XML Editor - Developer's Guide", "Packaging an add-on for XMLmind XML Editor integrated add-on manager".