mStar: enabling collaborative applications on the Internet
IEEE Internet Computing
The mStar environment features an agent-based architecture, implemented in Java, which preserves compatibility with the dominant Mbone paradigm for IP multicast. In particular, mStar supports developers in creating distributed, real-time multimedia software applications such as e-meetings. mSTAR: Enabling Collaborative Applications on the Internet D istributed, real-time multimedia applications on the Internet permit users to cooperate in new and more interesting ways for collaborative teamwork
... and Net-based learning. Missing from these existing applications, however, is an integrated software toolkit that supports creating multi-user applications for real-time audio and video. Separate Mbone components do exist for this purpose, but the lack of a uniform interface can confuse users and hinder reuse. The Java-based mStar shared software environment provides an integrated solution for generating, presenting, storing, and editing media in collaborative applications. It uses IP multicast to enable scalable distribution of real-time media and data among many simultaneous users. The powerful agent architecture that underlies the mStar environment simplifies creating new applications and encourages reuse. 1 mStar enhances both Net-based learning (distance education) and collaborative teamwork by presenting a uniform user interface for real-time audio and video, shared whiteboard, chat, voting, and distributed Web-based presentations. The system also supports on-demand recording and session playback. Although the immediate focus of this article is the mStar environment, several distributed applications, created using mStar, are currently in use by both academia and industry. The success of those applications prompted us to found Marratech AB (http://www.marratech.com/), which offers mStar-based products for IP-multicast-and desktop-based conferencing, and pursues ongoing R&D based on the mStar environment, as well. REQUIREMENTS Scalability and decentralized control were basic design requirements for mStar. Totally distributed applications do not rely on central servers, and they have no client-server interaction. To serve these needs, we chose IP multicast for media and data distribution.