Ever wondered how to create the .xml files that are used for installing components, modules, or plugins in Joomla! 1.5? What you need are the DTD files that describe the installer XML format. With these, plus an XML editor with a little code intelligence, making installer .xml files is easy.

The DTD files are available on dev.joomla.org, but are a little hard to find:

• http://dev.joomla.org/xml/1.5/component-install.dtd
• http://dev.joomla.org/xml/1.5/module-install.dtd
• http://dev.joomla.org/xml/1.5/plugin-install.dtd
• http://dev.joomla.org/xml/1.5/template-install.dtd

To use these, just add the following DOCTYPE reference at the top of your installer .xml file, just after the <?xml... directive, like this:

<!DOCTYPE install SYSTEM "http://dev.joomla.org/xml/1.5/module-install.dtd">

Then, if your XML editor has code intelligence, it should give you hints about getting that installer file right!