http://opencast.org/matterhorn/features#engage
Engage Tools
Basic embeddable media player for learners to engage with media
Two-screen media player, so that the learner can view the lecturer and slides at the same time
Interface for viewing closed captions, searching videos, and subscribing to an RSS feed Navigation timeline representing slide changes and keyword relevance Powerful in-media keyword search
Viewing hotspots, indicating which sections of the recording were most often watched Basic media annotation (coming soon)
All functionality accessible by keyboard and screen reader
Support for customization of player interface for localization