Zabbix - Track, record, alert and visualize performance and availability of IT resources
Zohno Z-Term - The Easy-to-Use Active Directory User Termination Tool
Statista - The Statistics Portal for Market Data, Market Research and Market Studies
Anturis - Anturis offers hosted server monitoring software (SaaS) for both Windows and Linux.
Montecarlito - MonteCarlito is a free Excel-add-in to do Monte-Carlo-simulations.
NIXStats - SaaS monitoring tool for window/linux servers and websites. Think up-time robot but with more features.