head to head · open source
opa vs UTMStack
opa has 12,256 GitHub stars, 1,686 forks, 310 open issues and last shipped yesterday. UTMStack has 582 stars, 76 forks, 141 open issues and last shipped yesterday. opa leads on adoption by 2,006% (12,256 vs 582 stars). opa is written in Go under Apache-2.0; UTMStack is written in TypeScript under AGPL-3.0. opa has attracted 14% as many forks as stars, UTMStack 13%. UTMStack was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (compliance), 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
| opa | UTMStack | |
|---|---|---|
| GitHub stars | ★ 12K | ★ 582 |
| License | Apache-2.0 | AGPL-3.0 |
| Written in | Go | TypeScript |
| Last push | 2026-09-19 | 2026-09-19 |
| Forks | ⑂ 1.7K | ⑂ 76 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick opa if
- You weight community size — 12K stars and counting
- You want the Apache-2.0 license terms
- Your stack matches Go
- You value the larger contributor base for long-term maintenance
pick UTMStack if
- You want the UTMStack feature set and don't need the biggest community
- You prefer the AGPL-3.0 license terms
- Your stack matches TypeScript
- You evaluated both and UTMStack fits your workflow better
About opa
Open Policy Agent (OPA) is an open source, general purpose policy engine that enables unified, context aware policy enforcement across the entire stack. It lives in the cloud native ecosystem as a graduated project in the Cloud Native Computing Foundation landscape, and it is written in Go under the Apache 2.0 license. Policy is expressed declaratively in the Rego language, and the project ships alongside a CLI, an HTTP REST API, a Go SDK, and editor tooling rather than as a single binary alone. The repository has been active for roughly eleven years, with 12,234 stars, 1,679 forks, and a last push dated 15 Septe…
About UTMStack
UTMStack is an open source, AGPL 3.0 unified threat management platform that merges SIEM and XDR into one system, built for security operations centre teams, incident responders and compliance owners who need real time log correlation, threat detection and audit evidence without handing their telemetry to a closed vendor.
read the full UTMStack overview →
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Frequently asked questions
Is opa or UTMStack more popular?
opa has 12,256 GitHub stars and UTMStack has 582. opa has the larger community by that measure.
Are opa and UTMStack free?
Both are open source. opa is licensed under Apache-2.0 and UTMStack under AGPL-3.0. Neither carries a licence fee.
What is the difference between opa and UTMStack?
opa is written in Go and UTMStack in TypeScript. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, opa or UTMStack?
Choose opa if you want the larger community (12,256 stars) or its Apache-2.0 licence terms. Choose UTMStack if its feature set, stack or AGPL-3.0 licence fits better. Both are self-hostable.