JEKray Licence

Version 1.0, 27 September 2026

JEKray, the optical bench simulator at jeksys.net/jek/tools/jekray.html, is copyright © 2025–2026 JEK Systems. All rights reserved. It is not open source: you can read its source code in your browser and on GitHub, but that does not give you permission to copy or reuse it. By using JEKray you agree to these terms.

1. What the software is

“The software” means the JEKray program and everything that ships with it: its code, its example benches, its glass and material data as compiled by JEK Systems, its documentation, its test suite and its user interface. It does not include the benches, files and results you make with it.

2. Free use

You may use the software free of charge, from our website or from a copy your browser saves for offline use, for:

• Personal use: learning, hobby projects and your own non-commercial work.
• Teaching: by students and teaching staff at schools, colleges and universities, including in lectures, lab classes, assignments and course notes.

3. Research and commercial use

Use by or for a research group, a company or any other organisation, beyond the teaching use in section 2, is licensed use. For now this use is also free: until JEK Systems offers paid licences, you may use the software for research and commercial work without charge. When paid licences are introduced, continued research or commercial use of new versions will need one. We will announce this on the JEKray product page before it takes effect. Contact [email protected] about licences.

4. What you may not do

Unless JEK Systems agrees in writing, you may not:

• copy, host, mirror or redistribute the software, or offer it to others as a download or a hosted service;
• modify it, translate it, or copy any part of its code or data into other software;
• sell, rent, sublicense or bundle it, or charge anyone for access to it;
• use its code, data or behaviour to build a competing product, including by training a machine-learning model on its source code;
• remove or hide its copyright notices, licence link or branding;
• get round any licence check or access control that a future version includes.

Reading the source to understand how a result was calculated, for your own checking, is fine.

5. Your work belongs to you

The benches, .jekray files, images, plots, reports and numbers you create are yours. You may share, publish and sell them freely, and you may share your own .jekray files with anyone. The example benches that come with the software stay ours; you may share benches built from them.

If JEKray contributes to published work, we would appreciate a mention, for example: “Simulated with JEKray (JEK Systems, jeksys.net).”

6. No warranty

The software is provided “as is”, without warranty of any kind, express or implied, including fitness for a particular purpose, accuracy and freedom from errors. It is a simulation: its results are models of real optics and can be wrong or incomplete. Check any result before you rely on it, and never use it as the basis for laser safety decisions. Follow your local laser safety rules and use proper eye protection.

7. Limitation of liability

To the fullest extent the law allows, JEK Systems is not liable for any loss or damage arising from use of the software or its results, including lost data, lost profit, damaged equipment and injury, whether direct, indirect or consequential. Where the law does not allow liability to be excluded, it is limited to the amount you paid for the software, if any. Nothing in these terms limits rights you have as a consumer that cannot be excluded by law.

8. Ending the licence

Your permission to use the software ends automatically if you break these terms. JEK Systems may also withdraw free access for any organisation with notice. When the licence ends you must stop using the software and delete any copies you hold. Sections 5 to 7 continue to apply.

9. Changes to these terms

JEK Systems may update these terms. A new version applies to versions of the software released after it is published here, and the version number and date at the top will change. Your benches and results remain yours under any version.

Contact

Licensing: [email protected]. Support: [email protected].