Jaeger

Jaeger is one of the foundational names in distributed tracing, and it deserves inclusion because it remains a real building-block tool rather than a marketing-layer observability product. It gives teams a way to collect, query, and visualize traces across distributed systems, helping them find latency bottlenecks, failed dependencies, and request-path problems. For many teams, Jaeger is the first serious tracing system they use before deciding whether to stay OSS or move to a more commercial observability platform.

Its economics are straightforward: Jaeger is Apache-2.0 open source and free to use. The tradeoff is that the team owns deployment, scaling, storage, upgrades, and operational complexity. That makes Jaeger appealing for engineering organizations that want tracing capability without SaaS license fees, but less ideal for buyers who really want a managed observability product. Compared with Honeycomb, Jaeger is far lighter on productized collaboration and pricing complexity because the real bill is infrastructure and operator time, not software subscription.