head to head · open source
zipkin vs pup
zipkin has 17,475 GitHub stars, 3,092 forks, 175 open issues and last shipped 3 months ago. pup has 1,040 stars, 138 forks, 12 open issues and last shipped 2 days ago. zipkin leads on adoption by 1,580% (17,475 vs 1,040 stars). zipkin is written in Java under Apache-2.0; pup is written in Rust under Apache-2.0. zipkin has attracted 18% as many forks as stars, pup 13%. pup was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (observability), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| zipkin | pup | |
|---|---|---|
| GitHub stars | ★ 17K | ★ 1.0K |
| License | Apache-2.0 | Apache-2.0 |
| Written in | Java | Rust |
| Last push | 2026-08-06 | 2026-11-03 |
| Forks | ⑂ 3.1K | ⑂ 138 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick zipkin if
- You weight community size — 17K stars and counting
- You want the Apache-2.0 license terms
- Your stack matches Java
- You value the larger contributor base for long-term maintenance
pick pup if
- You want the pup feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Rust
- You evaluated both and pup fits your workflow better
About zipkin
zipkin Zipkin is a distributed tracing system. It helps gather timing data needed to troubleshoot latency problems in service architectures. Features include both the collection and lookup of this data. If you have a trace ID in a log file, you can jump directly to it. Otherwise, you can query based on attributes such as service, operation name, tags and duration. Some interesting data will be summarized for you, such as the percentage of time spent in a service, and whether operations failed. The Zipkin UI also presents a dependency diagram showing how many traced requests went through each application. This…
read the full zipkin overview →
About pup
:dog2: Give Your Agent a Puppy: Introducing Pup CLI Every AI agent needs a loyal companion. Meet Pup — the CLI that gives your agents full access to Datadog's observability platform (because even autonomous agents need good tooling, not just tricks). What is Pup? A comprehensive, AI agent ready CLI covering a wide range of Datadog product domains. We've unleashed the full power of Datadog's APIs so your agents can fetch metrics, sniff out errors, and track down issues without barking up the wrong API tree. AI agents are the fastest growing interface for infrastructure management. Companies like Vercel and AWS…
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Frequently asked questions
Is zipkin or pup more popular?
zipkin has 17,475 GitHub stars and pup has 1,040. zipkin has the larger community by that measure.
Are zipkin and pup free?
Both are open source. zipkin is licensed under Apache-2.0 and pup under Apache-2.0. Neither carries a licence fee.
What is the difference between zipkin and pup?
zipkin is written in Java and pup in Rust. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, zipkin or pup?
Choose zipkin if you want the larger community (17,475 stars) or its Apache-2.0 licence terms. Choose pup if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.