Grafana Mimir is an open-source, scalable time series database for metrics, developed by Grafana Labs, which combines Cortex and previously commercial code, and is licensed under AGPLv3. Aimed at improving scalability and ease of use, Mimir features a horizontally scalable architecture, supports high cardinality queries, and offers enhanced documentation and configuration compared to Cortex. It can ingest metrics from various sources such as OpenTelemetry and Datadog, while maintaining compatibility with Prometheus. The project is part of Grafana's strategic shift to open-sourcing features from Grafana Cloud Metrics and Enterprise Metrics, aligning with the company's commitment to open-source and sustainable business models. Mimir is designed to be user-friendly and prevent lock-in, allowing users to migrate to other Prometheus-compatible solutions if desired. The launch of Mimir represents a significant step in Grafana's ongoing partnership with major cloud providers and its pursuit of an AGPL-licensed "LGTM" stack, which includes Loki, Grafana, Tempo, and Mimir.