If you have used linux, then you have most likely used TOP, it shows running processes on the computer and allows you monitor system resources as well as kill rouge processes. The trouble is it's fairly limited.

Enter the prospective replacement HTOP. You can get it like any other program in ubuntu "sudo apt-get install htop". It has a much more detailed readout, showing you the full number of processes, not just the top consuming ones. It also has a graphic display of each core's usage, load average, and uptime. Top that off with a customized interface, and easy searching among the processes. The icing on the cake is that it has lower usage than top. Get it today and try it out.