Website: https://prometheus.io/
Source Code: https://github.com/prometheus/prometheus
ΒΆ Description
"Prometheus is a free software application used for event monitoring and alerting. It records metrics in a time series database (allowing for high dimensionality) built using an HTTP pull model, with flexible queries and real-time alerting. The project is written in Go and licensed under the Apache 2 License, with source code available on GitHub, and is a graduated project of the Cloud Native Computing Foundation, along with Kubernetes and Envoy."