check_mk
Check_MK is an extension to the Nagios monitoring system that allows creating rule-based configuration using Python and offloading work from the Nagios core to make it scale better, allowing more systems to be monitored from a single Nagios server. It comes with a set of system checks, a mod_python and JavaScript based web user interface, and a module that allows fast access to the Nagios core. On top of Nagios it also adds additional features
linux solaris bsd open-source monitoring python
Icinga 2
Icinga 2 is the newest version of Icinga. It is a scalable and extensible monitoring system which checks the availability of your resources, notifies users of outages and provides extensive BI data.
linux windows bsd open-source monitoring 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
NGINX Amplify
Amplify is free monitoring tool for NGINX. Amplify offers extended NGINX metric collection, visualization, monitoring, and a static analyzer for NGINX configuration. It's simple to set up, yet powerful enough to bring the much needed insight into NGINX performance. Amplify is a SaaS developed and operated by Nginx, Inc. Keep NGINX up to date and secure with a native monitoring solution.
linux bsd free commercial logging monitoring metrics visualization security hardening errors
NXLog Enterprise and Community Editions
A multi-platform log collection suite to collect, parse, convert and send logs. Integrate with a wide range of products including SIEMs, log analytics dashboards, cloud services, databases, and more.
linux windows bsd solaris osx open-source free commercial logging
webhook
Configurable incoming webhook server
linux windows osx bsd solaris open-source ci cd orchestration