Graylog (Open Source)

Graylog is an open-source log management and SIEM platform allowing real-time ingestion, searching, and alerting on logs. It can route alerts to email or chat when errors or anomalies appear. Dashboards visualize system events, aiding incident correlation. Graylog suits security teams or DevOps wanting a free solution to unify logs from multiple sources, create queries for suspicious patterns, and trigger incident notifications for faster debugging or breach detection.