Pachyderm
The Pachyderm Project, created by the San Francisco Museum of (modern) Art and supported by the New Media Consortium (among others) was an effort to create a tool capable of developing media-rich online content via a simple-to-learn, template-based interface. It is now working and can be very powerful, if used properly. Its various templates can link audio, video, images and text in interesting ways, over a whole set of different pages. However, its current templates do not support a linear lesson, as we normally imagine education; instead, they support more nonlinear exploration, which can be powerful, but has limitations in education. Future versions should be open source and will allow users to create their own templates, which ought to correct this problem.