Ossim stands for Open Source Security Information Management. Its goal is to provide a comprehensive compilation of tools which, when working together, grant a network/security administrator with detailed view over each and every aspect of his networks/hosts/physical access devices/server/etc...
Besides getting the best out of well known open source tools, some of which are quickly described below these lines, ossim provides a strong correlation engine, detailed low, mid and high level visualization interfaces as well as reporting and incident managing tools, working on a set of defined assets such as hosts, networks, groups and services.