Apache SkyWalking
Apache APM platform for service topology, distributed tracing, metrics, logs, and cloud-native diagnostics.
Datadog
Checkmk Raw
Nagios-descended infrastructure monitoring with auto-discovery, pre-built service checks, and a polished web UI. Raw edition is GPL-2.0.
Coroot
eBPF-based APM for Kubernetes. Zero-instrumentation service maps and SLO dashboards.
Grafana
The de-facto open-source dashboard layer. Plug into Prometheus, Loki, Tempo, InfluxDB — one pane of glass.
Grafana Loki
Log aggregation inspired by Prometheus: index only labels, not full text. Cheap at scale.
Grafana Mimir
Grafana Labs' horizontally scalable, multi-tenant Prometheus-compatible long-term metrics store.
Grafana Tempo
High-scale distributed tracing backend. Stores traces in cheap object storage (S3, GCS).
Graylog
Mature log management and search with streams, pipelines, dashboards, and alerting. A practical Splunk alternative for log-heavy teams.
HyperDX
Open-source Datadog alternative that correlates logs, metrics, traces, and session replays in one UI.
Jaeger
The CNCF graduated distributed tracing system, originally from Uber. The default open-source choice for traces.
Netdata
Real-time per-second metrics with instant auto-discovery. Dashboards out-of-box, zero config.
OpenObserve
Rust-based, columnar, object-storage-backed. Claims 140x lower storage cost than Elasticsearch for logs.
OpenSearch Dashboards
Apache-2.0 fork of Kibana, paired with OpenSearch. The de-facto self-hosted alternative to Elastic for logs visualization.
Parseable
Rust-based log lake that writes Parquet to S3-compatible object storage. Compute-storage separated, indexless by design.
Perses
CNCF dashboarding tool with dashboards-as-code, static validation, and Kubernetes-native workflows. A GitOps-friendly Grafana alternative.
Prometheus
The CNCF-graduated, pull-based metrics store. Industry default for self-hosted metrics.
Quickwit
Rust search engine for logs and traces with sub-second queries directly against S3-compatible object storage.
Robusta
Kubernetes-native observability that turns Prometheus alerts into actionable, context-enriched events with auto-remediation playbooks.
SigNoz
Full-stack, OpenTelemetry-native APM + logs + metrics. The closest single-tool Datadog alternative.
Thanos
CNCF-graduated long-term storage and global query layer for Prometheus, backed by object storage.
Uptrace
OpenTelemetry APM backed by ClickHouse. Lean alternative to SigNoz.
VictoriaMetrics
Prometheus-compatible TSDB optimized for ingestion rate and storage cost. Single-binary by default, cluster mode for scale.
Zabbix
Classic agent-based monitoring suite for hosts, networks, and services. Pre-Prometheus old guard, still actively developed.
Zipkin
The original open-source distributed tracing system, born at Twitter in 2012. Single-binary simplicity, still maintained.