Fonlow Free Use, Self-Hosting and Redistribution Licence

Fonlow Free Use, Self-Hosting and Redistribution Licence

Ishihara Color Blind Test

Copyright © 2026 Fonlow. All rights reserved.

Licensor: Fonlow
Official Website: https://cbt.fonlow.org/
Backup Website: https://zijianhuang.github.io/cbt/

1. Purpose

This Licence permits individuals and organisations to freely use, copy, self-host, and redistribute the Ishihara Color Blind Test Progressive Web App ("Software"), including on private networks and organisational intranets.

Fonlow encourages organisations, including educational institutions, healthcare organisations, businesses, government organisations and other entities, to self-host the Software where access to external websites or Internet services is restricted.

This Licence does not transfer ownership of the Software or its copyright to the Licensee.

2. Definitions

For the purposes of this Licence:

"Licensor", "Fonlow", "we", "us" or "our" means Fonlow, the copyright owner and licensor of the Software.

"Licensee", "you" or "your" means any individual or organisation exercising rights granted by this Licence.

"Software" means the Ishihara Color Blind Test Progressive Web App and the files comprising or accompanying that PWA as distributed by Fonlow, including its HTML, CSS, JavaScript, images, Ishihara plates, configuration files, manifest, service-worker files, documentation and other associated materials, except for Third-Party Materials as described in Section 8.

"Self-Hosting" means installing and serving a copy of the Software from a web server, local server, private network, intranet, organisational network, public website or other infrastructure controlled or administered by the Licensee.

"Redistribute" or "Redistribution" means providing a copy of the Software to another person or organisation, whether by physical or electronic means.

3. Grant of Licence

Subject to the terms of this Licence, Fonlow grants you a non-exclusive, worldwide, royalty-free, perpetual licence to:

  1. use the Software for personal, educational, organisational, commercial-internal or other lawful purposes;

  2. download and make copies of the Software;

  3. install and Self-Host the Software on servers or other infrastructure under your control or administration;

  4. make the Software available to users through an intranet, private network, public website or other network;

  5. Redistribute copies of the Software to other persons or organisations;

  6. make reasonable modifications to the Software necessary for Self-Hosting, compatibility, accessibility, deployment, security or integration with your environment; and

  7. make backup copies of the Software.

No fee or royalty is payable to Fonlow for exercising the rights expressly granted by this Licence.

4. Free Access Requirement

The Software is intended to remain freely available to its users.

You may use the Software within a commercial, educational, governmental, healthcare or other organisation. You may also host the Software on infrastructure that is operated for commercial purposes.

However, you may not charge a user specifically for access to, or use of, the Software.

In particular, you must not:

  1. sell copies of the Software;

  2. rent or lease the Software;

  3. sell subscriptions whose essential purpose is to provide paid access to the Software;

  4. impose a licence fee or usage fee specifically for the Software; or

  5. otherwise commercially exploit the Software itself by charging users for access to it.

This restriction does not prohibit an organisation from charging for unrelated products or services that happen to be provided alongside or in connection with the Software, provided that the Software itself remains available to its users without a separate charge.

5. Self-Hosting and Intranet Deployment

You are expressly permitted to Self-Host the Software on:

  • an organisational intranet;

  • a private network;

  • a local web server;

  • an internal cloud environment;

  • an Internet-accessible web server;

  • an educational institution's network;

  • a healthcare organisation's network;

  • a corporate network; or

  • other infrastructure controlled or administered by you.

You do not need to obtain additional permission from Fonlow before deploying the Software in these environments, provided that you comply with this Licence.

You may configure the Software, web server, domain name, caching, service-worker behaviour, security settings and other infrastructure as reasonably necessary for your deployment.

6. Copyright and Attribution

The Software and its components remain the property of their respective copyright owners.

You must not remove, obscure or alter copyright notices, licence notices or other attribution notices included in the Software.

Where reasonably practicable, a Self-Hosted or Redistributed copy should retain an attribution such as:

Ishihara Color Blind Test — Copyright © 2026 Fonlow

You may add your organisation's own notice identifying your deployment, hosting, configuration or modifications, but you must not represent the Software itself as being originally created by your organisation or by another person.

You may state, for example:

"This is an organisation-hosted deployment of the Ishihara Color Blind Test, originally developed by Fonlow."

7. Modifications

You may modify the Software for your own deployment, including modifications necessary for:

  • intranet deployment;

  • local hosting;

  • accessibility;

  • compatibility;

  • security;

  • integration with other systems;

  • localisation or translation;

  • organisational configuration; and

  • technical maintenance.

Your modifications do not transfer ownership of the original Software to you.

You must retain the original Fonlow copyright notices relating to the original Software.

If you redistribute a modified version, you should clearly indicate that the version has been modified and, where reasonably practicable, identify the nature of the modifications.

Nothing in this Licence requires you to publish your modifications or source code.

8. Third-Party Materials

The Software may include, reference or depend upon third-party software, libraries, fonts, images, data, open-source components or other materials ("Third-Party Materials").

Third-Party Materials are not necessarily licensed under this Licence.

You must comply with the applicable licence terms for any Third-Party Materials included in or distributed with your copy of the Software.

Where a Third-Party Material has its own copyright or licence notice, that notice and applicable licence terms must be retained.

9. Trademarks and Branding

This Licence does not grant you ownership of, or unrestricted rights to use, any trademark, trade name, logo, service mark, domain name or other branding belonging to Fonlow.

You may identify the Software by its name, Ishihara Color Blind Test, and identify Fonlow as its copyright owner when reasonably necessary to describe your deployment.

You must not use Fonlow's branding in a manner that falsely suggests that your organisation's deployment is operated, sponsored, certified, endorsed or supported by Fonlow.

You may identify your installation as an organisation-hosted or modified version.

10. Medical and Testing Disclaimer

The Software is intended for preliminary screening and educational purposes only.

The Software must not be represented as a substitute for professionally administered colour vision testing.

The Ishihara plates presented on LED screens cannot replace professionally administered colour vision testing. Accurate Ishihara testing requires standardised printed plates viewed under controlled daylight-equivalent lighting conditions.

Results produced by the Software are indicative only and must not be represented as medical advice, diagnosis, certification or a definitive assessment of colour vision.

If a user has difficulty identifying numbers on multiple plates, receives inconsistent results, or has concerns about colour vision, the user should be directed to consult an optometrist or ophthalmologist for appropriate professional assessment.

This is particularly important where colour vision may affect daily activities, education or occupational requirements.

A Licensee must not modify or remove this disclaimer in a way that materially changes the nature or limitations of the Software.

11. Privacy and Data Handling

The Software is designed as a static Progressive Web App and does not actively collect, store or transmit personal information.

The Software does not provide forms, account registration, user tracking, advertising, analytics or other mechanisms intended to collect personal information.

The Software may use standard browser technologies such as local storage and service workers for functionality such as offline access and loading performance.

A Self-Hosted deployment may nevertheless be subject to logging, monitoring, security, proxying, analytics or other services implemented by the Licensee's web server, network, browser environment or other infrastructure.

The Licensee is responsible for the privacy and data-handling practices of its own hosting environment.

The current privacy information for the Software is published with the Software and may be updated by Fonlow from time to time.

12. No Obligation to Provide Support or Updates

This Licence does not require Fonlow to:

  • provide technical support;

  • provide updates;

  • provide security patches;

  • maintain compatibility with particular browsers or operating systems;

  • maintain the official website;

  • maintain the backup website; or

  • continue development of the Software.

A Self-Hosted copy may continue to operate independently of the official Fonlow website.

13. No Warranty

THE SOFTWARE IS PROVIDED "AS IS" AND "AS AVAILABLE", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, TO THE MAXIMUM EXTENT PERMITTED BY LAW.

WITHOUT LIMITING THE FOREGOING, FONLOW DOES NOT WARRANT THAT THE SOFTWARE:

  1. WILL BE ERROR-FREE;

  2. WILL BE AVAILABLE WITHOUT INTERRUPTION;

  3. WILL BE COMPATIBLE WITH EVERY DEVICE, BROWSER OR OPERATING SYSTEM;

  4. WILL MEET A PARTICULAR USER'S REQUIREMENTS; OR

  5. WILL PRODUCE ACCURATE OR CLINICALLY VALID COLOUR VISION TEST RESULTS.

14. Limitation of Liability

To the maximum extent permitted by applicable law, Fonlow shall not be liable for any direct, indirect, incidental, special, consequential or other loss arising from or relating to the use of, inability to use, modification of, Self-Hosting of, or reliance upon the Software.

Nothing in this Licence excludes, restricts or modifies any right, guarantee, condition or remedy that cannot lawfully be excluded, restricted or modified under applicable law.

15. Termination

This Licence remains in effect unless terminated in accordance with this Section.

If you materially breach this Licence, the rights granted to you under this Licence terminate automatically upon the breach, unless the breach is cured within a reasonable period after you become aware of it.

Upon termination, you must cease exercising the rights granted by this Licence and, where reasonably practicable, remove copies of the Software that are being used or distributed in breach of this Licence.

Termination does not affect rights or permissions that were lawfully exercised before termination.

16. No Transfer of Copyright

Nothing in this Licence assigns, transfers or conveys ownership of copyright or any other intellectual property rights in the Software to the Licensee.

Fonlow retains all rights not expressly granted by this Licence.

17. Reservation of Rights

All rights in the Software that are not expressly granted by this Licence are reserved by Fonlow.

In particular, this Licence does not grant rights to:

  • claim ownership of the Software;

  • register or claim Fonlow's trademarks as your own;

  • imply endorsement by Fonlow;

  • remove copyright or attribution notices;

  • charge users specifically for access to the Software; or

  • use the Software in a manner prohibited by applicable law.

18. Acceptance

By downloading, copying, installing, Self-Hosting, Redistributing, modifying or using the Software in a manner that requires permission under copyright law, you indicate your acceptance of this Licence.

If you do not agree to the terms of this Licence, you must not exercise the rights granted by this Licence.

19. Governing Law

This Licence is governed by the laws of Queensland, Australia, and the applicable laws of the Commonwealth of Australia.

To the extent permitted by law, the courts of Queensland, Australia, have jurisdiction over disputes arising from or relating to this Licence.

20. Licence Version

Licence: Fonlow Free Use, Self-Hosting and Redistribution Licence
Software: Ishihara Color Blind Test
Version: 1.0
Effective date: 15 August 2026
Copyright: © 2026 Fonlow. All rights reserved.

The official version of the Software is available from:

https://cbt.fonlow.org/

A backup distribution is available from:

https://zijianhuang.github.io/cbt/