htop
An interactive process viewer
htop is a cross-platform interactive process viewer. htop allows scrolling the list of processes vertically and horizontally to see their full command lines and related information like memory and CPU consumption. Also, system-wide information, like load average or swap usage, is shown. The information displayed is configurable through a graphical setup and can be sorted and filtered interactively. Tasks related to processes (e.g. killing and renicing) can be done without entering their PIDs...