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
Nagios Core
Nagios Core network monitoring software is a powerful, enterprise-class host, server, application, monitoring and alerting tool
linux solaris bsd open-source monitoring c
Pallet
A tool to provision and maintain servers across various cloud platforms as well as virtual machine platforms, without any dependencies. Provides cloud and operating system independence.
linux windows osx open-source cloud-paas clojure
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
Statman
Statman makes it possible to instrument and collect statistics from your high-traffic production Erlang systems with very low overhead. The collected data points are aggregated in the VM and can be sent to services like Graphite, Munin, New Relic, etc.
linux windows osx open-source monitoring erlang
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
Zipkin
A distributed request tracking system, useful for micro-service and distributed architectures written in Scala
linux windows osx open-source monitoring scala