</pre>
===Structure===
The [http://expath.org/spec/pkg EXPath specification] defines how the structure of a .xar archive shall look like. The package contains at its root a package descriptor named <code>expath-pkg.xml</code>. This descriptor presents some meta data about the package as well as the libraries which it contains and their dependencies on other libraries or processors. Apart from the package descriptor a .xar archive contains a directory which includes the actual XQuery libraries. For example the [http://www.functx.com/ FunctX XQuery Library] is packaged as follows: