Exploration and visualization of computer networks: Polyphemus and Hermes. POLYPHEMUS and HERMES are systems for exploring and visualizing computer networks at different abstraction levels. Today’s Internet is organized as Autonomous Systems (AS), each of them groups a set of networks under a single administrative authority (e.g. a private company). HERMES visualizes Internet as a set of ASes and interconnections between them. POLYPHEMUS is a complementary system that is able to look inside an AS and to visualize its networks at the level of the routers and their physical links.