It's difficult for me to categorize this useful utility, but it actually solves a common problem among Windows users.
Chances are you probably have the experience of a sudden slowdown of your PC, which is caused by either a decent application doing some real work (e.g. a large spreadsheet) or a misbehaving application overloading the CPU unintentionally. The end result is the same - they eat up 100% of the CPU time and the PC becomes unresponsive.
Process Tamer is a unique utility of its kind to rescue your PC from such unresponsive states. It accomplishes this by constantly monitoring other running processes. When it detects a CPU hogger, it reduces the priority of that process temporarily to restore the PC's responsiveness until the CPU usage is back to normal.
This sounds simple but it's really effective. I think Windows should have this capability built-in. Process Tamer also provides a Task Manager-like GUI where you can spot any CPU eater easily and terminate it if necessary. Extremely easy to use. Just install and forget. A license is required to run but it's free to register and it never expires.