Best Open Source Scheduling Software for 2026

SaaS scheduling tools charge $10-$50 per user per month for features that open source alternatives provide for free. For independent practitioners, small teams, and privacy-conscious organizations, open source scheduling software offers a way out of vendor lock-in, per-seat pricing traps, and third-party data exposure.

This guide covers 10 open source scheduling tools across appointment booking, employee scheduling, and group coordination. Each review includes the license type, self-hosting requirements, and an honest assessment of where the tool fits and where it falls short.

If you run a healthcare practice and want scheduling software you control, pay attention to the healthcare section below. No other comparison on this topic covers the specific needs of chiropractors, therapists, and independent practitioners.

What Makes Scheduling Software “Open Source”?

Open source means the source code is publicly available and licensed for modification and redistribution. But not all open source scheduling tools work the same way:

Permissive licenses (MIT, Apache 2.0): Use, modify, and distribute freely with minimal restrictions. You can fork the project, make changes, and even sell your modified version.
Copyleft licenses (AGPL, GPL): You can use and modify the code, but if you distribute it or offer it as a service, you must release your changes under the same license.
Open core model: The base product is open source, but premium features (team scheduling, enterprise support, HIPAA compliance) require a paid license.

Self-hosting is the primary advantage. When you run scheduling software on your own infrastructure, patient data, appointment records, and contact information stay under your control. This simplifies compliance with HIPAA, GDPR, and other data residency regulations.

Quick Comparison

Tool	Best For	License	Self-Hosted	Healthcare	API	Starting Price
dxcal	Healthcare practitioners	Open source	Yes	Yes (built for it)	Yes	Free
Cal.com	General-purpose scheduling	AGPL-3.0	Yes	No	Yes	Free (self-hosted)
Easy!Appointments	Simple appointment booking	GPL-3.0	Yes	No	Yes	Free
Rallly	Group scheduling and polls	AGPL-3.0	Yes	No	No	Free
TimeTrex	Employee/shift scheduling	AGPL-3.0	Yes	No	Yes	Free (Community)
Alf.io	Event ticketing	GPL-3.0	Yes	No	Yes	Free
Koalendar	Simple free scheduling	Proprietary	No	No	Limited	Free
OpenEMR	Medical practice management	GPL-2.0	Yes	Yes (EHR suite)	Yes	Free
Postiz	Social media scheduling	AGPL-3.0	Yes	No	Yes	Free
Plane	Project task scheduling	AGPL-3.0	Yes	No	Yes	Free

1. dxcal - Best for Healthcare Practitioners

dxcal is open source scheduling software purpose-built for chiropractors, therapists, and independent healthcare practices. Unlike general-purpose tools, it includes a calendar intelligence layer that matches appointments to practice goals and sends escalation-based reminders through multiple channels.

Key Features

Calendar intelligence: Goal matching with configurable escalation rules (reminders at T-30, T-14, T-7, T-3, T-1 days)
Multi-channel notifications: Email, Telegram, ntfy, Pushover - not just SMS and email
Rust-based core: 5x faster calendar parsing and event processing than JavaScript alternatives
Embeddable booking widget: White-label patient scheduling for your practice website
ICS feed aggregation: Sync Google Calendar, Outlook, and any ICS-compatible calendar
No per-seat pricing: Flat pricing regardless of team size

License and Self-Hosting

Open source. Self-hosted on your own servers or private cloud. Docker-based deployment. Patient data stays on your infrastructure.

Best For

Independent healthcare practices (1-5 providers) that need scheduling with data ownership and healthcare-specific workflows. See it running at SophieChiro.

Not Ideal For

Enterprise organizations needing deep EHR integration (consider NexHealth or OpenEMR). Teams wanting zero-setup cloud scheduling (consider Cal.com cloud).

2. Cal.com - Best for General-Purpose Scheduling

Cal.com is the most well-known open source scheduling platform, with 40,000+ GitHub stars and backing from major investors. It started as Calendso and has grown into a full scheduling infrastructure product.

Key Features

Round-robin and collective team scheduling
100+ integrations (Zoom, Google Meet, Teams, Stripe, HubSpot)
Customizable booking pages with embed support
Workflow automation (reminders, follow-ups, routing)
API access for custom integrations

License and Self-Hosting

AGPL-3.0 license. Self-hosting via Docker is supported but resource-intensive. Community reports suggest 2GB+ RAM minimum. Environment variable configuration is complex compared to simpler tools.

Pricing

Free (self-hosted). Cloud plans start at $12/user/month.

Best For

Tech teams and businesses that need a Calendly-level feature set with open source transparency. Strong developer community and extensive documentation.

Not Ideal For

Healthcare practices (no HIPAA features, no intake forms, no patient workflow). Non-technical users may struggle with self-hosting setup.

3. Easy!Appointments - Best for Simple Appointment Booking

Easy!Appointments is a lightweight, no-frills appointment scheduler that does exactly what the name implies. It has been around since 2013 and remains one of the simplest open source booking tools available.

Key Features

Straightforward appointment booking interface
Multi-provider support with individual availability settings
Google Calendar sync
Customer self-booking through a public booking page
Responsive design for mobile booking
Multi-language support (30+ languages)

License and Self-Hosting

GPL-3.0 license. Requires PHP + MySQL. Simple installation on any shared hosting or VPS. Lower resource requirements than Cal.com.

Pricing

Completely free. No paid tiers.

Best For

Solo practitioners and small businesses that need basic online booking without complexity. Ideal if you want something running in under an hour on cheap shared hosting.

Not Ideal For

Teams needing advanced features (workflow automation, payment processing, API-driven integrations). The UI is dated compared to modern alternatives.

4. Rallly - Best for Group Scheduling and Polls

Rallly (spelled with three L’s) is a Doodle alternative for finding meeting times that work for groups. It is not appointment booking software, but it solves the adjacent problem of coordinating schedules across multiple people.

Key Features

Create polls to find the best meeting time
No login required for participants
Time zone detection
Comments on poll options
Clean, modern interface

License and Self-Hosting

AGPL-3.0 license. Self-hostable via Docker. Simple setup with minimal dependencies.

Pricing

Free (self-hosted). Hosted version available at rallly.co.

Best For

Teams that need to coordinate meeting times without a full scheduling platform. Good companion to an appointment booking tool.

Not Ideal For

Appointment booking, patient scheduling, or any use case requiring provider availability management. Rallly is a polling tool, not a scheduling system.

5. TimeTrex - Best for Employee and Shift Scheduling

TimeTrex is a workforce management platform that covers employee scheduling, time tracking, payroll, and HR functions. The Community Edition is open source.

Key Features

Employee shift scheduling with rotation patterns
Time and attendance tracking
Payroll calculation
Job costing and invoicing
Mobile app for clock-in/clock-out
Compliance reporting

License and Self-Hosting

AGPL-3.0 (Community Edition). Self-hosted on Linux servers. More complex installation than appointment-focused tools.

Pricing

Free (Community). Professional and Enterprise editions are paid (pricing on request).

Best For

Businesses with shift workers (restaurants, retail, manufacturing, healthcare facilities with hourly staff). If you need employee scheduling rather than patient appointment booking, TimeTrex is the strongest open source option.

Not Ideal For

Appointment scheduling, patient booking, or solo practitioner use. This is workforce management, not client-facing scheduling.

6. OpenEMR - Best for Medical Practice Management

OpenEMR is a comprehensive open source electronic health records (EHR) system that includes appointment scheduling as part of a larger practice management suite. It has been in active development since 2002.

Key Features

Full EHR with clinical notes and prescriptions
Appointment scheduling with provider calendars
Patient portal for self-scheduling
Billing and insurance claim management
Lab integration
Multi-language, multi-facility support

License and Self-Hosting

GPL-2.0 license. Self-hosted on Linux/LAMP stack. Docker deployment available. Active community with commercial support options.

Pricing

Free. Commercial support and hosting available through certified vendors.

Best For

Medical practices that need a full EHR suite with integrated scheduling. If you need clinical documentation, billing, and scheduling in one system, OpenEMR covers all three.

Not Ideal For

Practices that only need scheduling. OpenEMR is a full EHR system, and using it solely for appointment booking is like buying an ambulance when you need a bicycle. The learning curve and setup complexity are significant.

7. Alf.io - Best for Event Ticketing

Alf.io is an open source event management and ticketing platform. While not traditional scheduling software, it handles event registration, seating, and check-in workflows.

Key Features

Event creation with multiple ticket categories
Online registration and payment
Check-in via QR codes
Waiting list management
Invoice generation
Integration with Stripe, PayPal, and other payment providers

License and Self-Hosting

GPL-3.0 license. Java-based, self-hosted via Docker or direct deployment.

Best For

Organizations running workshops, conferences, seminars, or group classes. Healthcare practices offering group sessions or wellness workshops could use this for event-specific booking.

Not Ideal For

Individual appointment scheduling. Alf.io is built for events with multiple attendees, not one-on-one provider-patient bookings.

8. Plane - Best for Project Task Scheduling

Plane is an open source project management tool that competes with Jira and Linear. Its scheduling features focus on sprint planning, task assignment, and project timelines.

Key Features

Issue tracking with Kanban and list views
Sprint planning and cycle management
Time tracking integration
Custom workflows and automations
API for custom integrations

License and Self-Hosting

AGPL-3.0 license. Docker-based self-hosting. Active development with regular releases.

Best For

Development teams and project managers who need task scheduling and sprint planning. Included here because “scheduling software” searches sometimes include project management tools.

Not Ideal For

Appointment booking or calendar scheduling. Plane schedules tasks, not meetings or patient visits.

Open Source Scheduling for Healthcare Practices

Generic open source scheduling tools miss critical requirements for healthcare:

Patient Data Privacy

When a patient books an appointment, their name, contact information, and reason for visit become protected health information under HIPAA. Self-hosted scheduling software keeps this data on infrastructure you control. No third-party vendor stores your patient records. No BAA (Business Associate Agreement) needed with a SaaS company because the data never leaves your systems.

Calendar Sync for Multi-Provider Practices

A 3-provider chiropractic practice needs unified availability across all practitioners. Patients should see only available slots for their preferred provider and service type. dxcal aggregates multiple calendar sources (Google, Outlook, ICS feeds) and presents unified availability through its booking widget.

No-Show Management

Healthcare no-show rates range from 5% to 30%. At $150 per missed appointment, a solo practitioner losing 3 slots per day to no-shows loses $450 daily. Multi-channel reminders via SMS, email, and push notifications reduce no-shows by 30-40%. dxcal’s escalation system sends reminders at configurable intervals, increasing urgency as the appointment approaches.

Why Generic Tools Fall Short

Cal.com and Easy!Appointments are solid scheduling tools, but neither understands healthcare workflows. They lack intake form collection, appointment type restrictions based on patient history, reminder escalation logic, and compliance-aware data handling. Building these features on top of a generic tool requires significant custom development.

dxcal is the only open source scheduling tool built from the ground up for independent healthcare practitioners. Read more in our patient scheduling software guide.

Self-Hosting vs Cloud: What to Consider

Infrastructure Requirements

Most open source scheduling tools run in Docker containers on a VPS (Virtual Private Server). Basic requirements:

Easy!Appointments: Shared hosting with PHP/MySQL. Cheapest option ($3-$10/month)
dxcal: Docker on a VPS. 1GB RAM minimum ($5-$15/month)
Cal.com: Docker with 2GB+ RAM. More dependencies ($10-$20/month)
TimeTrex: Dedicated server recommended. 4GB+ RAM ($20-$40/month)

Cost Comparison

	Self-Hosted	Cloud/SaaS
1 provider	$5-$15/month (VPS)	$10-$30/month (Calendly/Acuity)
3 providers	$5-$15/month (same VPS)	$30-$90/month (per-seat pricing)
5 providers	$10-$20/month (larger VPS)	$50-$150/month (per-seat pricing)

Self-hosting cost stays nearly flat as your team grows. SaaS costs scale linearly with headcount.

Maintenance Burden

Self-hosting means you handle updates, backups, and security patches. For non-technical practitioners, this is a real consideration. Options to reduce the burden:

Use managed hosting providers that handle updates
Set up automated backups (most Docker deployments support this)
Choose tools with simpler stacks (Easy!Appointments on shared hosting requires minimal maintenance)

How We Evaluated These Tools

Each tool was assessed on:

License: Is it truly open source, or open core with paywalled features?
Self-hosting ease: How complex is the Docker/installation setup?
Healthcare fit: Does it support healthcare workflows, compliance, and patient-facing booking?
API availability: Can developers integrate it into existing systems?
Community activity: Is the project actively maintained with recent commits and responsive maintainers?
Documentation quality: Can a non-developer follow the setup guide?

We prioritized tools with active development (commits within the last 6 months) and excluded abandoned projects regardless of feature count.

Frequently Asked Questions

Is Cal.com really free?

Cal.com is free to self-host under the AGPL-3.0 license. The cloud-hosted version starts at $12/user/month. Some premium features (team workflows, advanced routing) require a paid plan even on self-hosted instances through the “Enterprise” license. The core scheduling functionality is genuinely free and open source.

What is the best open source scheduling software for small practices?

For healthcare practices (chiropractors, therapists, wellness providers), dxcal offers healthcare-specific features with self-hosting and flat pricing. For non-healthcare businesses that need simple booking, Easy!Appointments provides the lowest-friction setup. For teams wanting a full-featured Calendly alternative, Cal.com offers the broadest feature set.

Can I self-host scheduling software without technical knowledge?

Easy!Appointments runs on standard shared hosting (the same hosting you would use for a WordPress site) and requires minimal technical knowledge. dxcal and Cal.com use Docker, which requires basic command-line familiarity. For truly non-technical users, consider a managed hosting service or start with a cloud plan and migrate to self-hosted later.

Is open source scheduling software HIPAA compliant?

HIPAA compliance is not a feature of software itself but a combination of technical safeguards, policies, and procedures. Self-hosted open source software gives you full control over where patient data is stored and how it is transmitted. This makes it easier to meet HIPAA technical requirements than SaaS tools where data resides on vendor servers. dxcal is designed with privacy-first architecture specifically for healthcare practices.

What is the difference between open source and free scheduling software?

Free scheduling software (like Calendly’s free tier) gives you limited features at no cost, but the code is proprietary and your data lives on the vendor’s servers. Open source scheduling software gives you the source code, the right to modify it, and the ability to run it on your own infrastructure. “Free” refers to price. “Open source” refers to freedom and control.

How does open source scheduling compare to Calendly?

Calendly offers a polished, zero-setup experience with extensive integrations. Open source alternatives like Cal.com and dxcal offer comparable features with added benefits: no per-seat pricing, data ownership, self-hosting, and customization. The trade-off is setup time and maintenance responsibility. For a detailed comparison, see our Calendly alternatives guide.

Start Scheduling on Your Terms

Open source scheduling software puts you in control of your data, your pricing, and your workflows. For healthcare practitioners who need scheduling built for clinical practice, dxcal combines open source transparency with features designed specifically for chiropractors, therapists, and independent practices.