set_package_properties(
  LibXML
  PROPERTIES
    TYPE
      OPTIONAL
    DESCRIPTION
      "a library providing XML and HTML support"
    URL
      "http://xmlsoft.org"
    PURPOSE
      "For the optional libical-glib interface"
)

set_package_properties("Doxygen" PROPERTIES
  DESCRIPTION "Documentation generator"
  URL "www.doxygen.org"
  PURPOSE "Generate HTML documentation from C sources")