head to head · open source
Cal.com vs koordinator
Cal.com has 48,529 GitHub stars, 15,154 forks, 1,432 open issues and last shipped 4 days ago. koordinator has 1,757 stars, 480 forks, 228 open issues and last shipped 3 days ago. Cal.com leads on adoption by 2,662% (48,529 vs 1,757 stars). Cal.com is written in TypeScript under MIT; koordinator is written in Go under Apache-2.0. Cal.com has attracted 31% as many forks as stars, koordinator 27%. koordinator 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 | koordinator | |
|---|---|---|
| GitHub stars | ★ 49K | ★ 1.8K |
| License | MIT | Apache-2.0 |
| Written in | TypeScript | Go |
| Last push | 2026-09-14 | 2026-09-15 |
| Forks | ⑂ 15K | ⑂ 480 |
| 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 koordinator if
- You want the koordinator feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Go
- You evaluated both and koordinator 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 koordinator
Koordinator is an Apache 2.0 licensed scheduling system written in Go for Kubernetes. It is positioned as a QoS based scheduling system for hybrid orchestration workloads, including microservices, web services, big data jobs, and AI jobs. The project lives in the cloud native Kubernetes ecosystem and is described through topics such as colocation, cost optimization, scheduling, and workload consolidation. The public repository reports 1,754 stars, 479 forks, 228 open issues, and a last push date of 2026 09 15.
read the full koordinator 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 koordinator more popular?
Cal.com has 48,529 GitHub stars and koordinator has 1,757. Cal.com has the larger community by that measure.
Are Cal.com and koordinator free?
Both are open source. Cal.com is licensed under MIT and koordinator under Apache-2.0. Neither carries a licence fee.
What is the difference between Cal.com and koordinator?
Cal.com is written in TypeScript and koordinator in Go. 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 koordinator?
Choose Cal.com if you want the larger community (48,529 stars) or its MIT licence terms. Choose koordinator if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.