Hardware Monitor is an application to read out all available hardware sensors in Macintosh computers. The program can display and visualize measured values in a large variety of fashions. It can also store and export readings. The application Temperature Monitor is available for free, but is limited to accessing temperature sensors only. The application Hardware Monitor is commercial shareware, but can access additional sensors if your computer is equipped with them. This includes the following sensor types:
* Battery sensors on portable computers
* Voltage sensors
* Current (amperage) sensors
* Fan speed sensors
* Sensors for pulse-width controlled fans
* Power and load sensors

Version 4.8:

* Support for Mac OS X 10.3 Panther has been removed. The required minimum OS version is now Mac OS X 10.4 Tiger.
* Added a feature to reset different aspects of display preferences for all sensors back to recommended default values. This new feature supersedes the former features to reset sensor display colors, data acquisition settings and customized labels.
* Added a feature to display 32/64 bit capabilities of the processor and the current mode of the kernel.
* Added a feature to display the unique identifier (UUID) of a computer.
* Added a feature to monitor the size of swap space memory which is actually in use.
* Added a feature to let the user define individual sets of remotely monitored computers in a network. It is now possible to connect to whole groups of monitored systems in one step.
* Added a new driver for monitoring of the internal thermal sensors of Intel processors which is also capable of supporting the 64 bit kernel version of Mac OS X 10.6 Snow Leopard.
* On PowerPC hardware, support for S.M.A.R.T. hard drive sensors accessed via SATA interfaces has been enhanced. The application will now accept the temperature sensors of unknown SATA drive models. (This has always been the standard on Intel-based computers.)
* The support for hard drive sensors controlled via proprietary drivers of Sonnet and FirmTek has been enhanced.
* By user request, a feature to suppress access to S.M.A.R.T. hard drive sensors has been added to the command-line version of the program.
* The output channel "Screen Display" will no longer try to keep its screen position if the user changes a multi-monitor configuration while the program is not running. This makes sure the Screen Display cannot become invisible when its target monitor has been removed.