Prime95 - Prime95 is a program that searches for new Mersenne prime numbers.
Udev Discover - A helping tool for udev testers, coders, hackers and consumers.
HeavyLoad - The individual test methods employed by HeavyLoad can be customized to fit your needs.
CPU Frequency Selector - Cinnamon CPU Frequency Selector Applet
Linpack Xtreme - Linpack Xtreme is a benchmark and the most aggressive stress testing software available today.
Novabench - NovaBench is a piece of analytical software that works to test the various limits of your computer. The software is completely free to use, and it runs at a lightning-fast pace. Read more about Novabench.