End User License Agreement (EULA)

Last updated: December 21, 2025

1. General

This End User License Agreement ("Agreement") governs your use of the website, including the chess engine and solar system simulator (collectively, the "Software"), as well as all multimedia content, data, and other materials (collectively, the "Content") provided by the author. By accessing or using the Software or Content, you agree to be bound by all terms of this Agreement.

2. License Grant

The author grants you a non-exclusive, royalty-free, non-transferable license to access and use the Software and Content for personal, non-commercial purposes only. Any commercial use (including resale, integration into paid services, or ad-based monetization) is strictly prohibited without the author’s prior written consent.

3. Restrictions

You shall not:

• modify, decompile, reverse engineer, or otherwise attempt to derive the source code;
• use automated tools (bots, scripts) to interact with the site;
• redistribute the Content or Software without the author’s permission, except where explicitly permitted (e.g., musical covers — see Section 7).

4. No Warranty

The Software and Content are provided "as is", without any warranties, express or implied, including but not limited to merchantability, fitness for a particular purpose, or non-infringement. The author does not warrant:

• preservation of chess games (games are not saved after browser closure);
• accuracy of astronomical data or visualizations;
• uninterrupted or error-free operation.

5. Limitation of Liability

The author shall not be liable for damages arising from your use of the Software or Content, including:

• loss of data or game progress;
• harm resulting from misinterpretation of astronomical or chess-related information;
• damages related to third-party services (Wikipedia, Windy.com, TheSkyLive, etc.).

6. Intellectual Property

All rights to the Software (source code, algorithms) and to the original Content (audio recordings, articles, fractals, chess games) are owned by the author, except for materials sourced from public domains:

• planetary textures: SolarSystemScope.com
• astronomical data: TheSkyLive.com, Wikipedia.org
• wind data: Windy.com
• chess engine concepts partially inspired by E.N. Kornilov’s book "Programming Chess and Other Logic Games" (BHV-Petersburg, 2005)
• solar system model based on approximations from O. Montenbruck & T. Pfleger, "Astronomy on the Personal Computer" (Piter, 2002)

Attribution does not imply endorsement or sponsorship by third parties.

7. Musical Covers and Copyright

Musical covers are distributed free of charge for educational purposes only. Upon download, you are solely responsible for verifying the copyright status of the underlying musical work. This is especially relevant for compositions by Sergei Vasilyevich Rachmaninoff, whose rights may still be valid in certain jurisdictions. The author assumes no liability for your infringement of third-party copyrights.

8. Feedback System

The on-site chat functions as a public suggestion and complaint book. Entries may be added or deleted by you or the author at any time without notice. Any user reserves the right to remove any message at their sole discretion.

9. Governing Law

This Agreement is governed by the laws of the Russian Federation. Any disputes shall be resolved in the courts of Moscow Oblast.

10. Language Priority

The Russian-language version of this Agreement is the official and controlling version. The English translation is provided solely for the convenience of international users. In the event of any discrepancy, the Russian text shall prevail.