Best Self-hosted Alternatives to Microsoft Bookings

Cal.com is an open-source scheduling and appointment booking platform often compared to Calendly. It lets individuals and teams publish booking pages, define availability rules, and manage confirmations and notifications, with strong customization and API-first extensibility.

Key Features

• Public booking pages and shareable booking links
• Availability management with buffers and daily/weekly/monthly limits
• Booking confirmations, rescheduling flows, and calendar event creation
• Automated reminders and follow-ups via email and SMS (via integrations)
• Team scheduling capabilities and admin controls for organizations
• API-driven architecture designed for embedding and white-label deployments

Use Cases

• Personal and team appointment scheduling (sales calls, interviews, office hours)
• Service-based bookings (consultations, classes, sessions)
• Building a custom scheduling product on top of a self-hosted platform

Cal.com is well suited for organizations that want control over scheduling workflows, branding, and data. It provides a modern web stack and an extensible foundation for building scheduling experiences for both internal teams and external customers.

Easy!Appointments is an open source web application for managing services, providers, and customer bookings through a public booking page and an admin backend. It is designed to be customizable for different scheduling workflows and can integrate with Google Calendar for synchronization.

Key Features

• Customer-facing booking interface for creating appointments
• Backend management for customers, appointments, services, and providers
• Working plans, availability settings, and booking rules
• Google Calendar synchronization for appointments
• Email notifications for booking-related events
• Translated user interface for multilingual deployments
• REST API for integrations and automation

Use Cases

• Booking management for clinics, salons, and other service-based businesses
• Scheduling interviews, consultations, or internal appointments with staff availability
• Embedding a booking flow into an existing website while sharing a database

Limitations and Considerations

• Deployment and upgrades require managing PHP version compatibility and database updates
• Some advanced capabilities mentioned in the ecosystem (e.g., payments, SMS, extended reporting) may require additional development or premium services

Easy!Appointments provides a solid foundation for organizations that need a self-managed scheduling system with provider/service structure and calendar synchronization. It fits well for teams wanting a customizable booking application that can be integrated into existing web environments.

LibreBooking is an open-source resource scheduling solution for organizations that need to manage reservations for shared resources. It provides a mobile-friendly web interface with extensibility options for custom workflows and integrations.

Key Features

• Multi-resource booking with configurable schedules and waitlists
• Role-based access control for administrators, resource managers, and users
• Quotas and credit-based controls to limit and govern reservations
• Usage reporting for tracking utilization and reservation activity
• Responsive Bootstrap-based UI with theming support
• Plugin-ready architecture for extending functionality
• Calendar integration via ICS for clients like Outlook and Thunderbird

Use Cases

• Booking shared resources such as rooms, equipment, or facilities
• Managing reservations with approval workflows, quotas, or fair-use rules
• Tracking utilization and producing reports for operations and planning

Limitations and Considerations

• Requires a PHP-compatible web stack and a supported SQL database for deployment
• Public demo environments may reset frequently and are not suitable for long-term testing

LibreBooking is well-suited for teams and institutions that need a straightforward, extensible reservation system with governance controls. It combines scheduling, access control, and reporting to help organizations manage shared resources reliably.

Seatsurfing is a workplace booking platform that enables employees to find and reserve desks, seats and rooms. It combines a REST API backend with web frontends to support hot-desking, room reservations and space planning in enterprises.

Key Features

• Core REST API backend implemented in Go for bookings and organization management
• Booking PWA (TypeScript/React) for end users and a separate Admin UI for configuration and management
• Support for uploading floor plans and arranging spaces with drag-and-drop layout tools
• Persistent storage using PostgreSQL and official Docker images for easy deployment
• Deployable via Docker Compose or Kubernetes; multi-architecture images (amd64, arm64) available
• Integrations for workplace platforms (example: Microsoft Teams and Confluence integrations are provided)
• Distributed as GPLv3-licensed software with an optional hosted SaaS offering and a free tier for small teams

Use Cases

• Hybrid workplace seat and desk reservations for distributed teams and enterprises
• Managing coworking spaces or shared offices with resource and room booking
• Visual floor plan management and hot-desking policies for facilities teams

Limitations and Considerations

• Primary mobile experience is delivered via a Progressive Web App rather than native mobile apps
• Distributed under GPLv3, which requires derivative works to comply with the license's copyleft terms

Seatsurfing is aimed at organizations that need a turnkey booking solution they can host or use as a managed service. It focuses on simple end-user booking flows, admin configurability, and standard containerized deployment options.

HiveDAV is a small, curlable free/busy scheduler that reads availability from a CalDAV calendar, stores it locally, and exposes a simple HTTP (curl) interface for availability and booking. It is designed to be run as a standalone service and is configured via environment variables.

Key Features

• Curl-first HTTP interface for querying week/day availability and simple booking commands.
• CalDAV discovery and calendar fetching to import events and compute free/busy slots.
• Local sqlite database storage for availability (single-file app.db) with atomic update flow.
• Ability to create bookings and send iCalendar invites via configured SMTP (supports STARTTLS).
• Simple build and deployment tooling: Makefile, Dockerfile present; runnable via go run . or containerized builds.

Use Cases

• Provide a minimal, scriptable free/busy endpoint for teams that already use CalDAV calendars.
• Automate room or resource booking by querying availability via curl and creating iCal invites.
• Integrate calendar availability into lightweight websites, chatbots or shell scripts that need a curlable scheduler.

Limitations and Considerations

• Uses the mattn/go-sqlite3 driver which requires gcc/CGO (CGO_ENABLED=1) to build; this affects static binary builds and cross-compilation.
• CalDAV servers vary in supported REPORT/query behavior; HiveDAV fetches all events and normalizes availability locally to maximize compatibility.

HiveDAV is a pragmatic tool for teams wanting a minimal, self-hosted free/busy service that interoperates with existing CalDAV calendars and simple curl-based workflows. It focuses on robustness with a small dependency surface and straightforward configuration.

Framadate is a web service offered by the Framasoft association for organising meetings and taking group decisions. The current (2025) version is based on the open-source Pollaris project (AGPL‑3) and provides date-based scheduling polls and classic option polls without mandatory registration.

Key Features

• Create date polls to propose multiple dates/times and collect participant availability.
• Create classic choice polls to decide between options without dates.
• Mobile-friendly, accessible UI designed for clarity and simpler poll creation.
• Results visualization in-page with export options for offline analysis.
• Administration link for poll owners to extend or manage polls; configurable end dates.
• Privacy-focused: minimal data collection, no advertising, and source code published under AGPL‑3.
• Multilingual interface and community-driven translations.

Use Cases

• Coordinate meeting times for volunteer groups, clubs, or small organisations.
• Quickly gather preferences or make simple group decisions without user accounts.
• Collect availability for events, workshops, or collaborative sessions.

Limitations and Considerations

• Default poll lifetime is limited (180 days by default); expired polls can be extended only within a fixed grace period before permanent deletion.
• The service is a new/beta deployment of Pollaris (feature parity with the older Framadate UI is still evolving); some legacy options (for example, a global "anyone can edit all votes" mode) may not yet be implemented.
• Moderation and usage are subject to the host association's terms and moderation charter; advanced enterprise integrations or SSO are not primary features.

Framadate is aimed at simple, low-friction scheduling and polling with an emphasis on data minimalism and free software principles. It is suitable for groups that need quick coordination without account management and for organisations that prioritise privacy and open code.