VoiceThread is a web-based tool that allows users to create multimedia presentations. It allows viewers to leave comments in five different ways and share presentations with others. Users can control how much the presentations are shared. VoiceThread does not require any software download and makes it easy to collaborate, comment on, edit, and embed presentations. It supports multimedia and online editing for collaboration, though it has limitations like not allowing simultaneous access and inconsistent browser functionality. VoiceThread can be used for teacher-centered presentations and student-centered sharing of experiences.