- [Bloonix](https://bloonix-monitoring.org/) - Bloonix is a monitoring solution that helps businesses to ensure high availability and performance. ([Source Code](https://github.com/bloonix)) `GPL-3.0``Perl`
- [Bosun](http://bosun.org/) - Monitoring and alerting system by Stack Exchange ([Source Code](https://github.com/bosun-monitor/bosun)) `MIT``Go`
- [Cabot](http://cabotapp.com/) - Monitoring and alerts, similar to PagerDuty.
- [Cabot](http://cabotapp.com/) - Monitoring and alerts, similar to PagerDuty. ([Source Code](https://github.com/arachnys/cabot)) `MIT``Python`
- [Cacti](http://www.cacti.net) - Web-based network monitoring and graphing tool.
- [cadvisor](https://github.com/google/cadvisor) - Analyzes resource usage and performance characteristics of running containers ([Source Code](https://github.com/google/cadvisor)) `Apache-2.0``Go`
- [checkmk](https://checkmk.com/) - Comprehensive solution for monitoring of applications, servers, and networks. ([Source Code](https://github.com/tribe29/checkmk)) `Python/PHP`