Open Source Rallly Alternatives

Cal.diy is the self-hosted, community-maintained edition of Cal.com. It's built for individuals who want to run their own scheduling infrastructure on their own servers, without depending on a hosted service. It's not a drop-in replacement for Cal.com's commercial product. Teams, organizations, SSO, and several enterprise features are absent. What it does offer is a solid personal scheduling setup you fully control.

The scheduling core is complete. You can create event types, set recurring bookings, run seated events, and accept payments through Stripe or PayPal. Availability rules are detailed:

• Buffer times, booking limits, and minimum notice keep your calendar from being overrun
• Date overrides and travel schedules let you adjust availability without rebuilding your whole setup
• Out-of-office blocks are supported natively

Calendar integrations cover most of the major options. Google Calendar, Outlook, Apple Calendar, CalDAV, Zoho, Exchange, and ICS feeds all connect. For video, you get Zoom, Google Meet, Microsoft Teams, Webex, Jitsi, and Cal Video (via Daily.co). Conferencing options like Whereby and Huddle01 are also available.

On the automation side, webhooks, Zapier, n8n, Make, and Pipedream are all supported. CRM connections (HubSpot, Salesforce, Close) work, as do messaging apps like Discord, Telegram, and WhatsApp. Analytics tools including GA4, PostHog, and Fathom can be plugged in. What's missing compared to Cal.com is workflow automation and routing forms.

The embed options (inline, popup, floating button) and the v2 REST API are both present, so you can integrate your booking page into other sites or build on top of it programmatically.

Authentication covers email/password, Google OAuth, and Microsoft OAuth. SAML SSO and SCIM sync are not included.

Cal.diy suits developers or technically confident individuals who want a self-contained scheduling tool on their own infrastructure and are comfortable managing a server, database, and security themselves. It's explicitly not recommended for production or commercial use. If you need team features, an admin panel, or enterprise-grade reliability, Cal.com's hosted product is the intended path.

Easy!Appointments is a powerful, completely free open-source appointment scheduling system that puts you in control of your booking process. Unlike subscription-based alternatives, this self-hosted solution eliminates monthly fees and booking commissions forever.

Key features that make scheduling effortless:

• Simple installation on your own server with full data ownership
• Google Calendar synchronization to integrate with existing workflows
• Highly customizable interface that adapts to any business type
• Multi-language support for international businesses
• Mobile-responsive design for bookings on any device

The platform has proven successful across diverse industries including healthcare, salons, education, restaurants, and recruitment agencies. With over 3,000 GitHub stars and a decade of active development, it offers the stability and community support professional businesses require.

Advanced capabilities include:

• Customer and staff management systems
• Email notification workflows
• Booking cancellation and rescheduling
• Service and provider categorization
• Waiting list functionality

For organizations requiring additional features, premium services are available including SMS integration, payment processing, custom development, managed hosting, and white-label solutions. The robust architecture ensures seamless integration with existing websites while maintaining complete control over your scheduling data.