KillSwitch - KillSwitch is an advanced system monitoring tool that is apart of

nmon - This systems administrator, tuner, benchmark tool gives you a huge amount of important performance...

Kiwi application monitor - Kiwi application monitor is a small program which lets you monitor your applications/processes, Windows and User activity.

vtop - vtop is a graphical command-line tool that uses unicode braille to chart CPU and memory usage.

Security Process Explorer - Security Process Explorer Give you detailed information about each and every process.

iftop - iftop does for network usage what top(1) does for CPU usage.