Chess Tutor - AI-powered Chess Training Application

Copyright (c) 2024 KaProblem (https://www.kaproblem.com / GitHub: stefan-kp)
All rights reserved.

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WHY DUAL LICENSING?
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Apple's App Store and Google Play Store terms are INCOMPATIBLE with GPL-3.0:
- App Store DRM conflicts with GPL's redistribution rights
- Platform restrictions violate GPL's freedom requirements
- FSF considers App Store distribution a GPL violation

Therefore, we CANNOT distribute GPL apps on mobile app stores.

Solution: Mobile builds exclude GPL code (Stockfish.js) and use API calls instead,
allowing proprietary licensing for app store compliance.

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IMPORTANT NOTICE REGARDING DUAL LICENSING
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This software is available under DUAL LICENSING terms:

1. GPL-3.0 License (Public Open Source Use)
   - Source code is licensed under GPL-3.0
   - You may use, modify, and distribute under GPL-3.0 terms
   - See LICENSE file for full GPL-3.0 text

2. Proprietary License (Copyright Holder Only)
   - Only the copyright holder (KaProblem/stefan-kp) may distribute under proprietary terms
   - Specifically applies to mobile app distributions (iOS/Android)
   - Required for App Store/Google Play compliance
   - Third parties DO NOT have this right

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THIRD PARTY RIGHTS AND RESTRICTIONS
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If you are NOT the copyright holder, you must comply with GPL-3.0:

✅ ALLOWED:
- Use the software under GPL-3.0 terms
- Modify and fork the source code
- Distribute modified versions under GPL-3.0
- Create web applications using this code (under GPL-3.0)

❌ NOT ALLOWED:
- Distribute proprietary (closed-source) versions
- Create proprietary mobile apps for App Store/Google Play
- Remove or bypass GPL requirements
- Claim exclusive rights to the software

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CONTRIBUTIONS
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By contributing code, documentation, or other materials to this project, you:

1. License your contributions under GPL-3.0 for public use
2. Grant the copyright holder (KaProblem/stefan-kp) the right to use your
   contributions under ANY license, including proprietary licenses
3. Represent that you have the legal right to make such grants
4. Understand that the copyright holder may include your contributions
   in proprietary mobile app distributions for App Store/Google Play

This dual licensing model is similar to those used by MySQL, Qt, and other
successful open source projects.

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DEPENDENCIES AND THIRD PARTY CODE
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This software includes or depends on:

- Stockfish.js (GPL-3.0) - Chess engine
  Used in web builds only, not included in mobile builds

- Next.js (MIT License)
- React (MIT License)
- Chess.js (BSD License)
- Other dependencies listed in package.json

Mobile builds do NOT include GPL-licensed components and use a network API
architecture instead, allowing proprietary distribution by the copyright holder.

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For questions regarding licensing or to request a proprietary license,
contact: KaProblem (https://www.kaproblem.com or stefan-kp via GitHub)

Last Updated: 2024-12-07
