head to head · open source
Windmill vs second-brain
Windmill has 18,360 GitHub stars, 1,136 forks, 852 open issues and last shipped yesterday. second-brain has 678 stars, 87 forks, 1 open issues and last shipped 1 months ago. Windmill leads on adoption by 2,608% (18,360 vs 678 stars). Windmill is written in Rust under a custom or non-standard licence; second-brain is written in Python under MIT. Windmill has attracted 6% as many forks as stars, second-brain 13%. Windmill was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 2 topic tags (ai-agents, open-source), 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
| Windmill | second-brain | |
|---|---|---|
| GitHub stars | ★ 18K | ★ 678 |
| License | Custom / other | MIT |
| Written in | Rust | Python |
| Last push | 2026-11-02 | 2026-09-26 |
| Forks | ⑂ 1.1K | ⑂ 87 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Windmill if
- You weight community size — 18K stars and counting
- You want the Custom / other license terms
- Your stack matches Rust
- You value the larger contributor base for long-term maintenance
pick second-brain if
- You want the second-brain feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches Python
- You evaluated both and second-brain fits your workflow better
About Windmill
Open source developer platform for internal code: APIs, background jobs, workflows and UIs. Self hostable alternative to Retool, Pipedream, Superblocks and a simplified Temporal with autogenerated UIs and custom UIs to trigger workflows and scripts as internal apps. Scripts are turned into sharable UIs automatically, and can be composed together into flows or used into richer apps built with low code. Supported languages: Python, TypeScript, Go, Bash, SQL, GraphQL, PowerShell, Rust, and more. Try it Website Docs Discord Hub Contributing Windmill Developer platform for APIs, background jobs, workflows and UIs…
read the full Windmill overview →
About second-brain
Quick install Sponsor Atlas Cloud is a full modal AI inference platform that gives developers a single AI API to access video generation, image generation, and LLM APIs. Instead of managing multiple vendor integrations, you connect once and get unified access to 300+ curated models across all modalities. Check out Atlas Cloud's new coding plan promotion for more budget friendly API access: Second Brain Example For an example of what Second Brain can do, visit It's an interactive art exhibition. Head to Head Evaluation Second Brain performs higher than OpenClaw and Hermes on harness bench, which measures "model…
read the full second-brain overview →
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Frequently asked questions
Is Windmill or second-brain more popular?
Windmill has 18,360 GitHub stars and second-brain has 678. Windmill has the larger community by that measure.
Are Windmill and second-brain free?
Both are open source. Windmill has no licence declared in this registry, and second-brain is licensed under MIT. Both are free to self-host.
What is the difference between Windmill and second-brain?
Windmill is written in Rust and second-brain in Python. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Windmill or second-brain?
Choose Windmill if you want the larger community (18,360 stars) or its Custom / other licence terms. Choose second-brain if its feature set, stack or MIT licence fits better. Both are self-hostable.