From the website:
The Rotisserie implements an innovative approach to online discussion that encourages measured, thoughtful discourse in a way that traditional threaded messaging systems cannot. In contrast to the completely asynchronous, broadcast-to-broadcast mode of existing threaded messaging systems, the Rotisserie adds structure to both the timing and the flow of the discussion. The timing of the discussion is broken into semi-synchronous rounds. Users are allowed to post responses at any time, but their responses are not published to other users until the deadline for the current round passes. This structure allows users to put significant thought into their responses rather than competing with other participants to post first. More important, this structure allows the system to control the flow of the discussion by distributing responses to specific users for further discussion at the end of each round, ensuring that every post is distributed to at least one other user for comment and that each user has exactly one post to which to respond. Lastly, the Rotisserie system includes support for discussion not only within a given class, but also between many different classes at once, allowing, for instance, Internet law classes at HLS and Cambridge to participate in a discussion about digital rights management with an engineering course at MIT.