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

Monit

An open source utility for managing and monitoring processes, programs, files, directories and filesystems

     

linux osx open-source monitoring process-mgmt c

Rex

A agent-less server orchestration tool built on Perl

     

linux windows osx open-source orchestration perl

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

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