head to head · open source
OpenProject vs calcure
OpenProject has 16,132 GitHub stars, 3,486 forks, 224 open issues and last shipped yesterday. calcure has 2,359 stars, 73 forks, 6 open issues and last shipped 20 days ago. OpenProject leads on adoption by 584% (16,132 vs 2,359 stars). OpenProject is written in Ruby under GPL-3.0; calcure is written in Python under MIT. OpenProject has attracted 22% as many forks as stars, calcure 3%. OpenProject 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
| OpenProject | calcure | |
|---|---|---|
| GitHub stars | ★ 16K | ★ 2.4K |
| License | GPL-3.0 | MIT |
| Written in | Ruby | Python |
| Last push | 2026-09-17 | 2026-08-29 |
| Forks | ⑂ 3.5K | ⑂ 73 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick OpenProject if
- You weight community size — 16K stars and counting
- You want the GPL-3.0 license terms
- Your stack matches Ruby
- You value the larger contributor base for long-term maintenance
pick calcure if
- You want the calcure feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches Python
- You evaluated both and calcure fits your workflow better
About OpenProject
OpenProject is a web based open source project management software for teams and organizations that need transparency, flexibility, and data sovereignty. It lives in the open source project management ecosystem, with Ruby as the repository language and Angular as a listed topic. The project is positioned as an open alternative to Asana and Basecamp, and the README also compares it with Jira, MS Project, Monday, and YouTrack.
read the full OpenProject overview →
About calcure
Calcure is a modern terminal user interface calendar and task manager written in Python under the MIT license. It runs in a terminal on Linux, macOS, or Windows, and it presents events, tasks, birthdays, and reminders in a customizable text based interface.
read the full calcure overview →
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Frequently asked questions
Is OpenProject or calcure more popular?
OpenProject has 16,132 GitHub stars and calcure has 2,359. OpenProject has the larger community by that measure.
Are OpenProject and calcure free?
Both are open source. OpenProject is licensed under GPL-3.0 and calcure under MIT. Neither carries a licence fee.
What is the difference between OpenProject and calcure?
OpenProject is written in Ruby and calcure 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, OpenProject or calcure?
Choose OpenProject if you want the larger community (16,132 stars) or its GPL-3.0 licence terms. Choose calcure if its feature set, stack or MIT licence fits better. Both are self-hostable.