A suite of Monitoring Plugins (formerly known as nagios-plugins)
Self-hosted, lightweight server and website monitoring and O&M tool
The open source post-building layer for agents
Monitor the stability of a Pandas or Spark dataframe
Floating window used to display current network speed, CPU & memory
Monitor temperature sensors, fan speed, voltage, load & clock speeds
The Active Monitoring System
Disk Inspection and Monitoring
The open source time series database
Open source monitoring system and time series database
Lightweight network IP scanner
An eye on your system
Scouter is open source APM (Application Performance Management) tool
Xray panel supporting multi-protocol multi-user expire day
Free open source tool for real-time PC hardware sensor monitoring
A distributed and high-performance monitoring system
The Open Source Security Platform
A Python based monitoring and tracking tool for Plex Media Server
The Network UPS Tools repository
sp_whoisactive
GRBL controller application with G-Code visualizer written in Qt
Application to comfortably monitor your Internet traffic
An interactive NVIDIA-GPU process viewer and beyond
Cross-platform application monitoring and error tracking software
Status page with uptime monitoring & API monitoring as code