The program atop is an interactive monitor to view the load on a Linux-system. It shows the occupation of the most critical hardware-resources (from a performance point of view) on system-level, i.e. cpu, memory, disk and network. It also shows which processes are responsible for the indicated load (again cpu-, memory-, disk- and network-load on process-level). The program atop can also be used to log system- and process-level information in raw format for long-term analysis. The program atopsar can be used to view system-level statistics as reports, similar to the program sar.