Compare software

Riemann vs Moira: catalog facts
Riemann	Moira
Free Free to download and run.	Free Free and open source; you host it yourself.
Linux, Self-hosted	Self-hosted
Low-latency stream processing of monitoring events Flexible rules written as Clojure code	Realtime alerting on Graphite and Prometheus metrics Separate API, checker and notifier services
Configuration requires learning Clojure syntax Keeps transient state rather than long-term storage	Needs an existing Graphite or Prometheus metrics setup Several services to deploy and maintain
Downloadable app, Self-hosted	Self-hosted
Closed source	Open source
License not stated	License not stated
No account needed	Not stated if an account is needed
Works offline	Not stated if it works offline
Official website Full listing and sources Checked October 1, 2026	Official website Full listing and sources Checked October 1, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.