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
Monit
An open source utility for managing and monitoring processes, programs, files, directories and filesystems
linux osx open-source monitoring process-mgmt c
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
Prevoty Application Monitoring & Protection (AMP)
Prevoty enables DevOps to inject security into your web applications and web services. Protection is provided at runtime from within the application itself, and stays with the app regardless of deployment method (cloud, on-premises, etc). Applications are protected against threats including XSS, SQLi, CSRF, command injection, etc. Works with Puppet, Chef, Ansible, Docker, Splunk, QRadar, ELK, and many others.
linux windows osx bsd commercial go java net nodejs perl php python ruby monitoring security hardening chef puppet ansible metrics-visualization ci
SignalFx
SignalFx is an advanced monitoring and alerting solution for modern infrastructure. With SignalFx, development and operations teams monitor, analyze, and alert in real-time on any time series data.
linux windows oxs commercial go python c metrics monitoring visualization
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