A new generation of e-learning development, based on synchronous groupware applications integration,
providing improved interactivity and pro-human relations, allows richer training experiences far
beyond a virtual classroom. Despite WWW service evolution, e-conferencing multimedia applications
remain “killer applications” and insensitive to resources degradation, in fact, the quality of service (QoS)
provided by the network is still a limitation impairing their performance. Such applications have found
in multicast technology an ally contributing for their efficient implementation and scalability. Additionally,
considering QoS as design goal at application level becomes crucial for groupware development,
enabling QoS proactivity to applications. The applications’ ability to adapt themselves dynamically according
to the resources availability can be considered a quality factor. Tolerant real-time applications,
such as videoconferences, are in the frontline to benefit from QoS adaptation. However, not all include
adaptive technology is able to provide both end-system and network quality awareness. Adaptation, in
these cases, can be achieved by introducing a multiplatform middleware layer responsible for tutoring
the applications’ resources (enabling adjudication or limitation) based on the available processing and
networking capabilities. Congregating these technological contributions, an adaptive platform has been
developed integrating public domain multicast tools, applied to a Web-based distance learning system.
The system is user-centered (e-student), aiming at good pedagogical practices and proactive usability for
multimedia and network resources. The services provided, including QoS adapted interactive multimedia multicast conferences (MMC), are fully integrated and transparent to end-users. QoS adaptation, when
treated systematically in tolerant real-time applications, denotes advantages in group scalability and
QoS sustainability in heterogeneous and unpredictable environments such as the Internet.
