Cal.diy vs Rallly
Both are free/open-source alternatives to Calendly. Here's how they stack up — verified facts, no spin.
Cal.diy
MIT-licensed community edition of the Cal.com scheduling codebase.
Cal.diy is the free, permissively-licensed fork Cal.com released in April 2026 after taking its commercial product closed-source. It carries over Cal.com's core booking engine — event types, buffer/booking-limit rules, Stripe/PayPal payments, and calendar/video integrations — under the MIT license, but the maintainers themselves describe it as community-maintained and recommend it for personal, non-production use rather than as a supported business tool.
Rallly
Open-source group scheduling and meeting-time polling.
Rallly solves a different but related problem: instead of one person publishing a booking link, it lets a group vote on the best time for a meeting across several proposed slots — the open-source answer to Doodle that also covers a chunk of Calendly's group-scheduling use case. It's actively developed and offers a hosted version (rallly.co) alongside a documented self-hosted Docker deployment.
Side by side
| Cal.diy | Rallly | |
|---|---|---|
| Sovereignty Score | 85 | 84 |
| Open source | Yes | Yes |
| Self-hostable | Yes | Yes |
| Local-first | Yes | Yes |
| License | MIT | AGPL-3.0 |
| Pricing | Free, self-hosted. No official managed hosting or support channel; Cal.com's paid hosted product is a separate, now closed-source, offering. | Free, self-hosted via Docker. A hosted version exists at rallly.co with an optional paid Pro tier for extra features. |
Cal.diy edges it on the Sovereignty Score, but the right pick depends on the trade-offs below.
Cal.diy
Strengths
- +Fully MIT-licensed — no open-core split, no feature paywall, free to modify or redistribute
- +Inherits a feature-rich booking engine: recurring events, seated events, payments, wide calendar/video integration list
- +REST API and embeddable booking widgets for building your own booking flow
- +Active repo (46k+ stars, commits within days) even post-fork
Trade-offs
- −Its own docs recommend it for personal use only and disclaim production readiness — 'use at your own risk'
- −No official support; the parent company no longer backs this codebase
- −Missing team/organization features, SSO/SAML, workflows, and routing forms that stayed in Cal.com's closed-source enterprise edition
- −Requires running Postgres + Redis + a Node.js host yourself — more moving parts than a single-binary app
- −Young as an independent project (forked April 2026); long-term maintenance commitment is unproven
Rallly
Strengths
- +Simple, focused tool that's genuinely good at the group-availability-poll problem
- +Active project (5,100+ stars, commits within the last day) with a documented Docker Compose deployment
- +AGPL-3.0 keeps improvements to a hosted fork open
Trade-offs
- −Not a 1:1 booking-page replacement — no per-provider service catalog, payments, or staff management like Calendly/Easy!Appointments
- −Primary distribution is the hosted rallly.co app; self-hosting is supported but secondary in the project's own messaging
- −AGPL-3.0 requires you to publish modifications if you offer a modified version as a network service
Facts verified 2026-07-09. Licenses and pricing change — spotted something out of date? That's a correction we want.