A free memory test program for x86 (PC) computers. Stand-alone diagnostic program that fits on one bootable floppy. Linux and Windows versions available with source code. http://www.memtest86.com
Monitors fan speeds, temperatures and voltages. It can access S.M.A.R.T. information and change fan speeds based on system temperatures, thus reducing noise and power consumption. http://www.almico.com/speedfan.php
Free diagnostics and benchmarking program running on Win32 platforms. Display information on the screen, print it, or save it to file in various formats like HTML, CSV or XML. http://www.lavalys.com/
SourceUSB - A professional software-based host USB analyzer. Captures and analyzes I/O requests for all USB devices. Targets Windows platforms and USB 1.x and 2.0. http://www.sourcequest.com
ModemChk makes it easy to check the results of your last connection, for reconfiguring your modem, comparing results, and checking line noise. Click the auto detect button or use the command line options to open and run an AT command of your choice. http://www.utilitysoft.co.nz/
Publisher of the DisplayMate utilities for testing, evaluating and improving image and picture quality for CRTs, analog and digital LCD monitors, video projectors, HDTVs, televisions, plasma displays and micro displays. http://www.displaymate.com/