This resource collection accepts an arbitrary number of nested
  resources and assumes that all those resources must be archives of one
  of the supported formats.  The resources returned
  by <archives> are the contents of the nested
  archives.
archives doesn't support any attributes.
<archives> has seven nested
    elements <ars>, <arjs>, <cpios>,
    <dumps>, <sevenzs>, <zips>
    and
    <tars> that
    are unions
    themselves, i.e. they accept arbitrary many resource(collection)s
    as nested elements.
The nested resources of <zips> are treated as ZIP archives, the nested resources of <tars> as TAR archives and so on.
Support for nested arjs, dumps
    and sevenzs has been added with the Compress Antlib
    1.5.
Copies all files from all jars that are on the classpath
    to ${target}.
    <copy todir="${target}">
      <cmp:archives xmlns:cmp="antlib:org.apache.ant.compress">
        <zips>
          <restrict>
            <path path="${java.class.path}"/>
            <name name="*.jar"/>
          </restrict>
        </zips>
      </cmp:archives>
    </copy>