Open Hardware Monitor - Monitors temperature sensors, fan speeds, voltages, load and clock speeds, with optional graph.
GLPI - GLPI is the Information Resource-Manager with an additional Administration- Interface.
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.
Lansweeper - Lansweeper discovers Windows, Linux and Mac machines in your network.
xScan - xScan is an application for viewing the behavior of your computer and Mac.
FusionInventory - Fork of the OCS Inventory project that enables users to inventory their IT assets.