head to head · open source
ponytail vs CL4R1T4S
ponytail has 142,629 GitHub stars, 7,653 forks, 270 open issues and last shipped 6 days ago. CL4R1T4S has 50,059 stars, 10,280 forks, 127 open issues and last shipped 10 days ago. ponytail leads on adoption by 185% (142,629 vs 50,059 stars). ponytail is written in JavaScript under MIT; CL4R1T4S is written in various languages under AGPL-3.0. ponytail has attracted 5% as many forks as stars, CL4R1T4S 21%. ponytail was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (prompt-engineering), 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
| ponytail | CL4R1T4S | |
|---|---|---|
| GitHub stars | ★ 143K | ★ 50K |
| License | MIT | AGPL-3.0 |
| Written in | JavaScript | — |
| Last push | 2026-09-14 | 2026-09-10 |
| Forks | ⑂ 7.7K | ⑂ 10K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick ponytail if
- You weight community size — 143K stars and counting
- You want the MIT license terms
- Your stack matches JavaScript
- You value the larger contributor base for long-term maintenance
pick CL4R1T4S if
- You want the CL4R1T4S feature set and don't need the biggest community
- You prefer the AGPL-3.0 license terms
- You evaluated both and CL4R1T4S fits your workflow better
About ponytail
Ponytail is an open source agent skill for JavaScript and LLM based coding tools that makes an AI agent write the minimum working code for a task, and it is built for developers and teams running agents such as Claude Code, Codex, or Cursor against real repositories.
read the full ponytail overview →
About CL4R1T4S
CL4R1T4S is an AGPL 3.0 repository of full extracted system prompts, guidelines and tools from the major AI models and agents — ChatGPT, Claude, Gemini, Grok, Perplexity, Cursor, Lovable, Replit and more — for anyone who wants to know what instructions sit behind the AI systems they use.
read the full CL4R1T4S overview →
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Frequently asked questions
Is ponytail or CL4R1T4S more popular?
ponytail has 142,629 GitHub stars and CL4R1T4S has 50,059. ponytail has the larger community by that measure.
Are ponytail and CL4R1T4S free?
Both are open source. ponytail is licensed under MIT and CL4R1T4S under AGPL-3.0. Neither carries a licence fee.
What is the difference between ponytail and CL4R1T4S?
ponytail is written in JavaScript and CL4R1T4S in various languages. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, ponytail or CL4R1T4S?
Choose ponytail if you want the larger community (142,629 stars) or its MIT licence terms. Choose CL4R1T4S if its feature set, stack or AGPL-3.0 licence fits better. Both are self-hostable.