Baïkal vs Rallly
| Tagline | Lightweight CalDAV and CardDAV server based on sabre/dav | Self-hosted scheduling polls to find the best time for a group to meet |
| Category | Scheduling & Booking | Scheduling & Booking |
| Replaces | Calendly, Acuity Scheduling | Calendly |
| GitHub stars | 3.2k | 5.1k |
| Language | PHP | TypeScript |
| License | GPL-3.0 | AGPL-3.0 |
| Self-host difficulty | 3/5 Moderate | 3/5 Moderate |
| Deploy options | Docker Manual | One-Click Docker Docker Compose Manual |
| Managed hosting | ||
| Last updated | 5 days ago | today |
| View repo | View repo |
Where each falls short
The honest trade-offs — what you give up with each, versus the proprietary tools they replace.
Baïkal
- No web-based calendar or scheduling UI for end users; requires a CalDAV client app
- No public booking page or availability-sharing feature comparable to Calendly
- Development activity has slowed; some sabre/dav edge cases may go unpatched
- HTTPS and reverse-proxy setup is manual and not guided
Rallly
- Focused on group availability polling rather than one-on-one booking pages, so it does not replace Calendly's personal booking links.
- No direct calendar-availability checking or two-way calendar sync to auto-block busy times.
- No built-in payment collection or paid-appointment support.
- Requires PostgreSQL and SMTP configuration to self-host; not a single-binary deploy.
Bottom line
Both are a similar lift to self-host; choose Rallly for the larger community and ecosystem. Rallly has seen more recent development. Open each guide below for deploy steps and the full feature gap.