Preventon Antivirus - Preventon Free Antivirus
ServerSuit - ServerSuit is a browser based program that enables remote Linux administration, monitoring, website hosting, and server setup automation.
ClamWin - ClamWin is an Open Source Virus Scanner and Spyware Detector.
RedGate SQL Monitor - SQL Monitor helps you and your team find issues – before they become problems
COMODO Internet Security - Download Free Internet Security Software for Complete protection against viruses and attacks of your computers. Know what's new in Comodo Internet Security.
Nagios - Complete monitoring and alerting for servers, switches, applications, and services