- [Adagios](http://adagios.org/) - Web based Nagios interface for configuration and monitoring (replacement to the standard interface), and a REST interface. ([Source Code](https://github.com/opinkerfi/adagios)) `AGPL-3.0``Docker/Python`
- [Beats](https://www.elastic.co/beats/) - Single-purpose data shippers that send data from hundreds or thousands of machines and systems to Logstash or Elasticsearch. ([Source Code](https://github.com/elastic/beats)) `Apache-2.0`
- [Collectd](https://collectd.org/) - System statistics collection daemon. ([Source Code](https://github.com/collectd/collectd)) `MIT``C`