Nagios - Complete monitoring and alerting for servers, switches, applications, and services

Gitwin - Enable your Windows system as a powerful and secure Git repository. Supports ssh, http(s) transports. Gitweb with highlighter and gravatar support available.

Zabbix - Track, record, alert and visualize performance and availability of IT resources

Zenoss Core - Zenoss (Zenoss Core) is an open source application, server and network management platform based on...

Linux Dash - A drop-in, low-overhead monitoring web dashboard for a Linux machine.

Netdata - Monitor your servers, containers, and applications, in high-resolution and in real-time.