M3 is a distributed time series database designed to integrate seamlessly with existing tools such as Prometheus, InfluxDB, and Grafana. It enables painless upgrades of individual components in an existing data platform. M3 supports the Prometheus protocol, allowing for easy migration from Prometheus to M3 without changing the server agent configuration. Additionally, it is compatible with the InfluxDB wire protocol, facilitating seamless migrations and adoption as a time series database. The integration with Grafana is also straightforward, making visualization of large amounts of time-series data simple. Overall, M3 offers excellent integrations, successful migration projects, and impressive scalability, making it an attractive option for developers working with time-series data.