1. Drupal

• Overview: Drupal is a highly customizable and flexible open-source CMS that has many modules available for user registration, appointment scheduling, and billing.
• Key Features:
  • Extensive user registration and management tools.
  • Modules for scheduling and appointment booking.
  • Can integrate with payment gateways for billing and invoicing.
  • Supports complex workflows and user roles, suitable for managing patients and doctors.
• Pros: Scalable, secure, and can be customized heavily.
• Cons: Requires some technical knowledge to set up and maintain.
• Website: Drupal.org

2. WordPress with Plugins

• Overview: WordPress, paired with specialized healthcare plugins, can handle doctor-patient portals, billing, and appointment scheduling.
• Key Plugins:
  • WP Medical: Allows you to create doctor profiles, manage appointments, and even add booking features.
  • WooCommerce: Can be used for handling payments and billing.
  • Bookly: Appointment scheduling plugin that integrates well with payment systems.
• Pros: Easy to set up, with a wide range of plugins to cover different functions.
• Cons: Performance might be an issue with large-scale use unless optimized.
• Website: WordPress.org

3. Joomla with Medical Extensions

• Overview: Joomla is another open-source CMS with strong community support, offering several extensions for building healthcare portals.
• Key Extensions:
  • Doctor Appointment Booking System: A component that handles appointment scheduling and doctor availability.
  • Billing and Invoicing: Extensions for payment handling.
• Pros: Flexible and powerful for managing user roles and permissions.
• Cons: More complex than WordPress but highly customizable.
• Website: Joomla.org

4. OpenEMR

• Overview: OpenEMR is a free, open-source electronic medical record (EMR) and practice management system, tailored specifically for healthcare providers.
• Key Features:
  • Patient and doctor management.
  • Appointment scheduling.
  • Billing and payment tracking.
  • Prescription management.
• Pros: Designed specifically for healthcare with compliance to HIPAA.
• Cons: Requires significant setup and is more complex due to medical functionalities.
• Website: OpenEMR

5. Chikitsa

• Overview: Chikitsa is a free and open-source clinic management software designed for managing appointments, patients, and billing for small clinics and hospitals.
• Key Features:
  • Doctor and patient management.
  • Appointment scheduling.
  • Billing, invoicing, and payment integration.
• Pros: Built for healthcare and simpler to set up compared to larger platforms like OpenEMR.
• Cons: Limited in terms of complex workflow management.
• Website: Chikitsa

6. HospitalRun

• Overview: HospitalRun is another open-source solution aimed at hospitals and healthcare facilities, with offline capabilities.
• Key Features:
  • Designed for medical staff to manage appointments, billing, and patient records.
  • Offline-first system for clinics with limited internet access.
  • Payment and billing integrations.
• Pros: Focused on healthcare with great offline capabilities.
• Cons: May not be as customizable for non-hospital use cases.
• Website: HospitalRun

7. Odoo (Community Edition)

• Overview: Odoo is an open-source ERP with a variety of modules that can be used to manage appointments, doctors, patients, billing, and payments.
• Key Features:
  • Patient and doctor management.
  • Appointment scheduling.
  • Billing and invoicing modules.
• Pros: Highly flexible and scalable. Can be customized with a range of plugins and integrations.
• Cons: Requires some setup knowledge and customization.
• Website: Odoo

Mendix (Community Edition)

• Overview: Mendix is a low-code platform with a free community edition that allows you to build custom applications quickly. You can design a doctor-patient management system tailored to your needs, including registration, appointments, billing, and more.
• Features:
  • Full flexibility for building custom solutions.
  • Rapid development with drag-and-drop functionality.
  • You can integrate third-party APIs for payments.
• Pros: Extremely flexible and scalable, perfect for custom needs.
• Cons: Requires some technical knowledge to customize.
• Website: Mendix

2. LibreHealth

• Overview: LibreHealth is an open-source health IT project designed for healthcare facilities and clinical environments. It is the successor to OpenMRS and is actively maintained.
• Features:
  • Modular and customizable for patient and doctor management.
  • Supports scheduling, billing, and patient records management.
  • Can be integrated with payment systems for invoicing.
• Pros: Built specifically for healthcare with active community support.
• Cons: It is more complex to set up and configure, aimed at medical environments.
• Website: LibreHealth

3. OpenMRS

• Overview: OpenMRS (Open Medical Record System) is an open-source platform that allows users to design and manage medical records and patient interactions. It’s widely used in clinics and hospitals and supports customization for appointments and billing.
• Features:
  • Designed for managing medical records and appointments.
  • Extensible with modules for billing and payments.
  • Built for healthcare environments.
• Pros: Scalable and flexible, suitable for clinics and hospitals of various sizes.
• Cons: More technical setup is required compared to simpler CMS platforms.
• Website: OpenMRS

4. Nextcloud with Healthcare Plugins

• Overview: Nextcloud is a popular open-source collaboration platform that can be extended to include healthcare-related functionalities such as appointment booking, billing, and secure patient-doctor communication through various plugins.
• Features:
  • File storage and sharing, with privacy and compliance for sensitive information.
  • Integrates with plugins for calendars (appointment scheduling) and messaging.
  • You can set up invoicing and billing via integration with third-party tools.
• Pros: Secure, with strong community support, and HIPAA compliance for the healthcare sector.
• Cons: Requires customization and extension through plugins.
• Website: Nextcloud

5. Remedy (a FHIR-based healthcare solution)

• Overview: Remedy is an open-source healthcare management system built on top of the Fast Healthcare Interoperability Resources (FHIR) standard, which is designed for patient management, appointments, and medical record keeping.
• Features:
  • Supports medical record management.
  • Offers appointment scheduling.
  • Can be extended with payment and billing functionalities.
• Pros: Built for healthcare with modern, standard-based architecture.
• Cons: Requires technical setup and knowledge of FHIR standards.
• Website: Remedy Open-Source

6. Baikal

• Overview: Baikal is a lightweight and secure open-source platform for managing appointments and calendars, which can be adapted for a doctor-patient appointment system.
• Features:
  • Supports calendar and contact management (perfect for scheduling).
  • Can integrate with other systems for more complex workflows like payments and billing.
• Pros: Lightweight, easy to set up, with a focus on simplicity.
• Cons: Lacks built-in healthcare functionalities, so it would require significant customization.
• Website: Baikal

OpenClinic GA

• Overview: OpenClinic GA is an open-source hospital management system that is well-suited for clinics, hospitals, and health care providers. It covers appointments, billing, and medical record management.
• Key Features:
  • Appointment scheduling and management.
  • Electronic medical records (EMR) for patients.
  • Supports billing and invoicing.
  • Lab and pharmacy management.
• Pros: Designed specifically for healthcare with built-in features to manage medical services.
• Cons: May be too comprehensive if you only need a simple platform for appointments and billing.
• Website: OpenClinic GA

2. Bahmni

• Overview: Bahmni is an open-source hospital system that integrates electronic medical records, billing, and appointments into one platform. It is based on OpenMRS but provides a more modern and user-friendly interface.
• Key Features:
  • Comprehensive patient registration, appointment booking, and billing.
  • Integrated with ERP for inventory and billing.
  • Ideal for clinics and hospitals with modern user interfaces.
• Pros: Tailored for healthcare, scalable, and integrates various medical functions.
• Cons: Requires technical setup and is more suited for full medical facilities.
• Website: Bahmni

3. OpenHospital

• Overview: OpenHospital is an open-source healthcare management system that focuses on clinics and hospitals in developing regions. It is lightweight and includes features like patient registration, appointment scheduling, and billing.
• Key Features:
  • Patient registration and appointment management.
  • Handles medical records, billing, and lab results.
  • User-friendly interface, focused on ease of use for clinics.
• Pros: Lightweight, easy to use, and designed for low-resource environments.
• Cons: Lacks the extensive features of more complex systems, but ideal for small to medium-sized healthcare operations.
• Website: OpenHospital

4. Medkey (Medical Practice Management)

• Overview: Medkey is a powerful open-source medical practice management software. It helps with appointments, medical records, billing, and managing doctor-patient interactions.
• Key Features:
  • Appointment management system.
  • Customizable billing, invoicing, and payment integration.
  • Comprehensive patient management features, including medical history tracking.
• Pros: Designed with doctors and medical professionals in mind.
• Cons: Requires some setup and technical knowledge, but very customizable.
• Website: Medkey

5. PulseTile (Open Source EMR Interface)

• Overview: PulseTile is an open-source EMR interface built on top of the EtherCIS platform, designed to support medical records, patient management, and scheduling. It’s lightweight but can be expanded to include various healthcare services.
• Key Features:
  • User-friendly patient dashboard for doctors.
  • Integrated patient records and history tracking.
  • Can be extended to handle appointments, billing, and payments.
• Pros: Modular, customizable, and can be adapted to a variety of healthcare use cases.
• Cons: Still in its early stages of development and requires technical expertise.
• Website: PulseTile

6. GNU Health

• Overview: GNU Health is a free, open-source health and hospital information system designed for hospitals, doctors, and other healthcare providers. It supports patient management, billing, and medical records.
• Key Features:
  • Comprehensive patient management system.
  • Handles appointments, medical records, and billing.
  • Integrates with financial and accounting systems for easy invoicing.
• Pros: Complete health management system with strong community support.
• Cons: Complex to set up and requires technical knowledge.
• Website: GNU Health