head to head · open source
Cal.com vs Saturn
Cal.com has 48,529 GitHub stars, 15,154 forks, 1,432 open issues and last shipped 4 days ago. Saturn has 2,305 stars, 686 forks, 279 open issues and last shipped 10 months ago. Cal.com leads on adoption by 2,005% (48,529 vs 2,305 stars). Cal.com is written in TypeScript under MIT; Saturn is written in Java under Apache-2.0. Cal.com has attracted 31% as many forks as stars, Saturn 30%. Cal.com 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.
← all 8884 open source comparisons
Side by side
| Cal.com | Saturn | |
|---|---|---|
| GitHub stars | ★ 49K | ★ 2.3K |
| License | MIT | Apache-2.0 |
| Written in | TypeScript | Java |
| Last push | 2026-09-14 | 2025-11-12 |
| Forks | ⑂ 15K | ⑂ 686 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Cal.com if
- You weight community size — 49K stars and counting
- You want the MIT license terms
- Your stack matches TypeScript
- You value the larger contributor base for long-term maintenance
pick Saturn if
- You want the Saturn feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Java
- You evaluated both and Saturn fits your workflow better
About Cal.com
Cal.diy is a fully open source, community maintained fork of Cal.com, stripped of all enterprise and commercial features. It provides a self hosted scheduling platform built on the T3 stack (Next.js, tRPC, Prisma, Tailwind CSS, Zod), licensed under MIT with no proprietary code or license keys required.
read the full Cal.com overview →
About Saturn
Saturn is distributed job scheduling platform. Created by VIP.com. Java based. Apache 2.0 licensed. GitHub shows 2305 stars, 686 forks, last push 2025 11 12. It is listed under business software scheduling and event management. Repository age is 10 years. Lives in open source Java scheduling ecosystem. Provides fault tolerant and high available job scheduling service. Targets time based jobs across many machines.
read the full Saturn overview →
More in Business Software
Related comparisons
More Scheduling & Event Management projects
Compare either of these against the rest of the Scheduling & Event Management field.
Frequently asked questions
Is Cal.com or Saturn more popular?
Cal.com has 48,529 GitHub stars and Saturn has 2,305. Cal.com has the larger community by that measure.
Are Cal.com and Saturn free?
Both are open source. Cal.com is licensed under MIT and Saturn under Apache-2.0. Neither carries a licence fee.
What is the difference between Cal.com and Saturn?
Cal.com is written in TypeScript and Saturn in Java. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Cal.com or Saturn?
Choose Cal.com if you want the larger community (48,529 stars) or its MIT licence terms. Choose Saturn if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.