NotificationCenterExample
on userNotificationCenter_shouldPresentNotification_(notificationcenter, notification)
    return 1
end userNotificationCenter_shouldPresentNotification_

on notification(aTitle, aSubtitle, aMessage)
    set userNotification to current application's NSUserNotification's alloc()'s init()
    set userNotification's title to aTitle
    set userNotification's subtitle to aSubtitle
    set userNotification's informativeText to aMessage
    current application's NSUserNotificationCenter's defaultUserNotificationCenter's deliverNotification_(userNotification)
    current application's NSUserNotificationCenter's defaultUserNotificationCenter's setDelegate_(me)
    userNotification's release()
end notification

notification("THIS IS TEST", "notification test", "This is notification test from cocoa applescript applet.")
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Cocoaブリッジしているので通常のAppleScriptではなくCocoa-Applescript AppletかCocoa-Applescript Applicationで動くコードです。