We present in this paper a new model for an algorithm visualization system. Our model views the visualization system as an integral part of a broader distance learning environment. As such, it supports the heterogeneity of the Internet the visualization is expected to run on and the diversity of the expected users. It does so by defining a few ways for handling multi-level visualizations. First, a visualization can run in various abstraction levels of the algorithm, depending on the familiarity of the students with the studied materials. Second, a visualization can use various levels of graphics, depending on the capabilities of the client machines. Third, the messages sent between the machines can be of various levels, depending on the communication loads. Another important aspect of a distance learning environment, which is supported by our model, is to facilitate collaboration and data sharing between the students and the instructor and between the students themselves. This paper also presents a system, MAVIS, that realizes the model, and demonstrates its use on case studies.