Udev Discover - A helping tool for udev testers, coders, hackers and consumers.
SpeedFan - Hardware monitor for Windows that can access digital temperature sensors located on several 2-wire SMBus Serial Bus. Can access voltages and fan speeds and control fan speeds. Includes technical articles and docs.
CPU-Z - CPU-Z is a freeware that gathers information on some of the main devices of your system : Processor name and number, codename, process, package, cache levels.
smcFanControl - [Download] smcFanControl 2.
PC Wizard - THIS SOFTWARE IS NO LONGER MAINTAINED.PC-Wizard is an utility designed to analyze and benchmark your computer system. CPU and memory subsystem (caches, RAM ...). Graphics and video. Hard disks, CD/DVD, Removable/FLASH medias.
Argus Monitor - Argus Monitor is for monitoring and analyzing the temperature and the health status of the hardware parts of the system.