collectd
A daemon that collects system performance statistics periodically, and provides tons of plugins to store and analyze these values
linux windows osx open-source monitoring c
Instrumental
Instrumental is a real-time, high-scale application and server monitoring tool with intelligent alerts, a powerful query language, and free development accounts.
linux windows oxs free metrics commercial metrics monitoring visualization php ruby python net java nodejs
PowerShell Desired State Configuration
DSC is a new management platform in Windows PowerShell that enables deploying and managing configuration data for software services and managing the environment in which these services run.
linux windows powershell open-source commercial config-mgmt
Sentry
Automate error tracking to find and fix issues before your users even experience a crash. Sentry is open-source, real-time, and loved by 100,000 developers around the world.
osx windows linux open-source errors nodejs ruby python php java monitoring
Supervisord Monitor
Supervisord Monitor is multi server monitoring tool for supervisor - watch, start and stop all your supervisord instances and servvices from one place.
linux windows osx open-source monitoring provisioning php process-mgmt
Zabbix
An open source, enterprise-class monitoring framework
linux windows osx open-source monitoring c