Self-hosted, lightweight server and website monitoring and O&M tool
The Network UPS Tools repository
A suite of Monitoring Plugins (formerly known as nagios-plugins)
A utility to safely generate malicious network traffic patterns
Lightweight network IP scanner
Floating window used to display current network speed, CPU & memory
Monitor temperature sensors, fan speed, voltage, load & clock speeds
Monitoring Tool for your IT Environment
Apache HertzBeat(incubating) is a real-time monitoring system
A full packet capturing, indexing, and database system
Open source monitoring system and time series database
A distributed and high-performance monitoring system
Community-based GPL-licensed network monitoring system
Application to comfortably monitor your Internet traffic
Monitor and troubleshoot transactions in complex distributed systems
pg_activity is a top like application for PostgreSQL server activity
An eye on your system
Performance Co-Pilot
A simple program to monitor your network/data usage
A fancy self-hosted monitoring tool
Monitorix is a free, open source, lightweight system monitoring tool
SQL operating system instrumentation and monitoring framework
SNMP Exporter for Prometheus
Zeek is a powerful network analysis framework
Visibility into servers, applications, and infrastructure