VoiceThread is a collaborative, asynchronous tool that acts like a video conference over time (not at the same time) or a discussion board that allows you to hear and see others, not just read what they write. All participants can navigate at their own pace and leave comments about any added content (e.g., images, documents, and videos) via microphone, webcam, telephone, text or even another uploaded file. Users can annotate on the screen while commenting, and pick which comments are shown through moderation.