Abstract: In one aspect, in general, a system comprises a computer system configured to enable users to interact with a collection of learning groups, each learning group associated with at least one group leader and having members each approved by a group leader, and within each learning group, instances of training programs chosen by the group leader from a library of training programs available to the system, each instance of a training program includes a collection of lessons, each lesson includes a multimedia portion and an interactivity portion, the interactivity portion enabling asynchronous interaction among the members of the learning group, the multimedia portion being available to users other than members of the learning group, and the interactivity portion being available only to the members of the learning group