# HACK: On all other platforms, assume that Mono can be used to run
      #       any CLR application.
      #
      return [isMonoInstalled]
    }
  }

  #
  # NOTE: This procedure verifies that the specified value is indeed a valid
  #       package name.  The packageName argument is the value to verify.
  #       This procedure may raise script errors.
  #
  # <internal>
  proc verifyPackageName { packageName } {
    if {[string length $packageName] > 0 && \
        ![regexp -nocase -- {^[A-Z][0-9A-Z\.]*$} $packageName]} then {
      error "package name must be alphanumeric and start with a letter"
    }
  }

  #
  # NOTE: This procedure verifies that the specified value is indeed a valid
  #       patch level.  The patchLevel argument is the value to verify.  This
  #       procedure may raise script errors.
  #
  # <internal>
  proc verifyPackagePatchLevel { patchLevel } {
    if {[string length $patchLevel] > 0 && \
        ![regexp -nocase -- {^\d+\.\d+(?:\.\d+){0,2}$} $patchLevel]} then {
      error "patch level must use dotted decimal notation"
    }
  }

  #
  # NOTE: This procedure verifies the combination of language and version
  #       specified by the caller.  The language argument must be one of the
  #       literal strings "eagle", "tcl", or "client".  The version argument
  #       must be one of the literal strings "8.4", "8.5", or "8.6" when the
  #       language is "tcl" -OR- the literal string "1.0" when the language
  #       is "eagle".  When the language is "client", the version match the

    } elseif {$language eq "client"} then {
      if {![regexp -- {^1\.0(?:\.\d+)+$} $version]} then {
        error "unsupported client version"
      }

      set isClient true
    } else {
      error "unsupported package language"
    }
  }

  #
  # NOTE: This procedure returns the name of the current platform.  There are
  #       no arguments.  An empty string will be returned if the name of the
  #       current platform cannot be determined for any reason.

      win64-ia64 -
      win64-x64 {
        #
        # NOTE: This platform name is supported verbatim, do nothing.
        #
      }
      default {
        error "unsupported package platform"
      }
    }
  }

  #
  # NOTE: This procedure issues a request to an HTTP(S) server.  It returns
  #       the raw response data verbatim.  It may raise a script error.  It

  #       file needs to be downloaded and verified for the downloaded file.
  #
  # <public>
  proc checkForHigherVersion { language version platform packageName usePgp } {
    variable clientDirectory
    variable persistentRootDirectory

    verifyPackageName $packageName
    verifyLanguageAndVersion $language $version isClient
    verifyPlatform $platform platform

    set temporaryDirectory [getUniqueTempDirectory pkgd_ver_]

    if {$isClient} then {
      set persistentDirectory $clientDirectory

  proc downloadAllPlatforms { language version packageName fileNames usePgp } {
    variable baseUri
    variable branchName
    variable platformsUri
    variable platformsUrn

    #
    # NOTE: Verify that the package name, language, and version are correct.
    #
    verifyPackageName $packageName
    verifyLanguageAndVersion $language $version isClient

    set temporaryDirectory [getUniqueTempDirectory pkgd_plat_]

    set localFileName [file join $temporaryDirectory manifest.txt]
    file mkdir [file dirname $localFileName]

    set useAutoPath [string is true -strict \
        [getDictionaryValue $options -useAutoPath]]

    set allowUpdate [string is true -strict \
        [getDictionaryValue $options -allowUpdate]]

    #
    # NOTE: Verify that the package language, version, and platform are
    #       correct.
    #
    verifyLanguageAndVersion $language $version isClient
    verifyPlatform $platform platform

    set temporaryDirectory [getUniqueTempDirectory pkgd_lib_]

    if {$isClient} then {
      set persistentDirectory $clientDirectory