The complexity of Grid environments is growing as more projects and applications appear in this quick-evolving domain. Widespread applications are distributed over thousands of computing elements, various communities of users are aggregated into virtual organizations, resources availability is more and more dynamic and final locations of jobs cannot be foreseen. In such contexts, new paradigms and constraints which deeply impacts monitoring and visualization possibilities must be addressed. As nodes and even sites appear and disappear quickly in grid, automated resources and services discovery must be performed and regularly launched with an adequate frequency compared to the dynamicity of grid elements. The numerous production sites interconnected by grids have their own security policies and system administration principles and procedures, which can eventually be outsourced. A global Grid monitoring system must be efficient and not intrusive to respect security policies and do not i...