Software Licence Agreement
Last updated: 3 July 2026
This Software Licence Agreement ("Agreement") is between CurveHDD Limited ("Licensor") and the individual or organisation ("Licensee") that has purchased or been granted access to the CurveHDD software platform. By installing or using the software you accept the terms of this Agreement.
1. Grant of licence
Subject to payment of applicable fees and the terms of this Agreement, the Licensor grants the Licensee a non-exclusive, non-transferable, revocable licence to use the CurveHDD software for the Licensee's internal professional engineering purposes during the term of the licence.
Licences are issued on a named-seat basis. Each seat permits one named individual to use the software. Seats may not be shared, transferred, or used concurrently by more than one person.
Design run output is metered by tokens. Generating a full HDD design package (drawings and QA report) consumes tokens from the Licensee's balance. Token usage is recorded server-side.
2. Restrictions
The Licensee must not:
- Copy, distribute, sublicense, sell, or transfer the software or any licence;
- Reverse-engineer, decompile, disassemble, or otherwise attempt to derive the source code or underlying algorithms of the software, except to the extent required by applicable law;
- Remove or alter any proprietary notices, labels, or marks;
- Use the software to develop a competing product;
- Use the software in any manner that infringes the intellectual property rights of the Licensor or any third party.
3. Intellectual property
The CurveHDD software, including its design algorithms, source code, user interface, and documentation, is the exclusive intellectual property of CurveHDD Limited, part of the Curve IP Group. A patent application is pending in relation to key aspects of the software's design methodology. All rights not expressly granted in this Agreement are reserved.
4. Engineering disclaimer
CurveHDD is a professional design aid. All designs produced by the software must be independently checked and approved by a suitably qualified and experienced engineer before use on any construction project. The Licensor accepts no liability for any loss, damage, or injury arising from the use of designs produced by this software without independent verification.
Where designs affect safety-critical infrastructure — including railways, highways, utilities, or structures — the engineer of record is solely responsible for verifying the design independently.
5. Third-party components
The software incorporates open-source components under various licences (including LGPL, MIT, Apache 2.0, and BSD). A full list of third-party components and their licence texts is provided in the THIRD_PARTY_NOTICES.txt file included in the installation directory. Nothing in this Agreement affects any rights you may have under those open-source licences.
In particular, this software incorporates PySide6 (Qt framework) licensed under LGPL v3. In accordance with LGPL requirements, the Qt DLLs are distributed in replaceable form within the installation directory.
6. Data and privacy
The software transmits data to Curveform cloud services for licence authentication and AI-assisted report generation. No personal data is retained beyond the duration of a session. The Licensee is responsible for ensuring it has authority to transmit any project or personal data processed through the software.
7. Term and termination
This licence remains in effect for the term of the paid licence period. The Licensor may terminate this licence immediately if the Licensee breaches any term of this Agreement. On termination, the Licensee must cease all use of the software and destroy any copies in its possession.
8. Limitation of liability
To the fullest extent permitted by law, the Licensor's total liability to the Licensee under or in connection with this Agreement shall not exceed the licence fees paid by the Licensee in the twelve months preceding the claim. The Licensor shall not be liable for any indirect, consequential, special, or incidental loss. Nothing limits the Licensor's liability for death or personal injury caused by negligence, or for fraud.
9. Governing law
This Agreement is governed by the laws of England and Wales. Any dispute shall be subject to the exclusive jurisdiction of the courts of England and Wales.