Methods, systems, and computer program products are disclosed for differential dynamic content delivery. Typical embodiments include providing a session document for a presentation, wherein the session document includes a session grammar and a session structured document; receiving a prerecorded presentation...http://www.google.com.hk/patents/US7428698?utm_source=gb-gplus-share專利 US7428698 - Differential dynamic delivery of content historically likely to be viewed
