head to head · open source
Outline vs zotero-AI-Butler
Outline has 40,765 GitHub stars, 3,595 forks, 78 open issues and last shipped 2 days ago. zotero-AI-Butler has 1,768 stars, 98 forks, 17 open issues and last shipped 3 days ago. Outline leads on adoption by 2,206% (40,765 vs 1,768 stars). Outline is written in TypeScript under a custom or non-standard licence; zotero-AI-Butler is written in TypeScript under AGPL-3.0. Outline has attracted 9% as many forks as stars, zotero-AI-Butler 6%. Outline was the more recently maintained of the two, and both are self-hostable with no licence fee.
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
| Outline | zotero-AI-Butler | |
|---|---|---|
| GitHub stars | ★ 41K | ★ 1.8K |
| License | Custom / other | AGPL-3.0 |
| Written in | TypeScript | TypeScript |
| Last push | 2026-09-29 | 2026-09-28 |
| Forks | ⑂ 3.6K | ⑂ 98 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Outline if
- You weight community size — 41K stars and counting
- You want the Custom / other license terms
- Your stack matches TypeScript
- You value the larger contributor base for long-term maintenance
pick zotero-AI-Butler if
- You want the zotero-AI-Butler 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 zotero-AI-Butler fits your workflow better
About Outline
Outline is an open source knowledge base application built with React and Node.js, designed for teams needing a fast, collaborative documentation platform. It runs as a self hosted service or via a hosted option at getoutline.com, and its source code powers the public instance along with all supporting services. The project lives in the JavaScript/TypeScript ecosystem and uses MobX for state management.
read the full Outline overview →
About zotero-AI-Butler
zotero AI Butler is a free, open source Zotero plugin written in TypeScript and licensed under AGPL 3.0 that calls large language models to read the PDFs already sitting in a Zotero library and writes the results back as native Zotero notes, built for researchers, students, and anyone whose "read later" pile has outgrown their reading time.
read the full zotero-AI-Butler overview →
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Frequently asked questions
Is Outline or zotero-AI-Butler more popular?
Outline has 40,765 GitHub stars and zotero-AI-Butler has 1,768. Outline has the larger community by that measure.
Are Outline and zotero-AI-Butler free?
Both are open source. Outline has no licence declared in this registry, and zotero-AI-Butler is licensed under AGPL-3.0. Both are free to self-host.
What is the difference between Outline and zotero-AI-Butler?
Outline is written in TypeScript and zotero-AI-Butler 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, Outline or zotero-AI-Butler?
Choose Outline if you want the larger community (40,765 stars) or its Custom / other licence terms. Choose zotero-AI-Butler if its feature set, stack or AGPL-3.0 licence fits better. Both are self-hostable.