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.
Macs Fan Control - Macs Fan Control is an iMac, MacBook Pro, MacBook Air, Mac Mini and Mac Pro fan control that is the solution of two basic issues namely noise problems and overheating problems.
Open Hardware Monitor - Monitors temperature sensors, fan speeds, voltages, load and clock speeds, with optional graph.
Argus Monitor - Argus Monitor is for monitoring and analyzing the temperature and the health status of the hardware parts of the system.
xScan - xScan is an application for viewing the behavior of your computer and Mac.
iMac HDD Fan Control - iMac HDD Fan Control is an HDD fan control for the Mac operating systems by using which the Mac users can control the speed and noise of the fan of the Mac.