Monitors process activities, and list those heavy cpu, memory or disk consumers in the indicator applet.
System load indicator can monitor system's CPU usage, memory usage and disk activities. If a process uses too much CPU or memory, or doing heavy disk reading/writings, this application will find it out and list it in the indicator applet menu.
It will use some weather icons as its indicator icon. If no process is chunking the system, it will display a clear-moon-night icon, when some process is slowing down the system, icons of cloudy, shower, heavy-shower will appear according to the system load.
However, due to the use of application indicator, which is relatively new and not very popular, only ubuntu 10.04+ can display the application indicator menu, other distributions may only use a status icon instead.