Nagios v3.4.1
Nagios is a host and service monitor designed to inform you of network problems before your clients, end-users or managers do. It has been designed to run under the Linux operating system, but works fine under most *NIX variants as well.
Sniffing Problems A Mile Away
CrystalDiskInfo is a HDD/SSD health monitoring utility. It displays basic HDD information, monitors S.M.A.R.T. values and disk temperature.
Memtest86 is a thorough, stand alone memory test for x86 architecture computers. BIOS based memory tests are a quick, cursory check and often miss many of the failures that are detected by Memtest86.