Trademark & affiliation
Our relationship to NumPy, SciPy and NumFOCUS, and how the Tessero name may be used.
Tessero is an independent project and is not affiliated with or endorsed by NumPy, SciPy or NumFOCUS.
NumPy, SciPy and NumFOCUS
NumPy and SciPy are open-source projects licensed under the BSD-3-Clause license. Their names, and the names of their contributors, are used by Tessero only to describe compatibility and to give credit, never to endorse or promote Tessero. We do not use their logos, colours or visual identity. “NumPy”, “SciPy” and “NumFOCUS” are the marks of their respective owners.
In keeping with clause 3 of the BSD-3-Clause license, we do not use the names of the NumPy or SciPy projects or their contributors to endorse or promote Tessero without permission. We describe Tessero as “NumPy- and SciPy-compatible” or as “verified against NumPy and SciPy”, and never as a port of NumPy or SciPy to PHP. See the Acknowledgments.
The Tessero name
Tessero™ is a trademark of Douglas Johnson. It is the subject of a pending U.S. trademark application (USPTO Serial No. 50143724, International Class 009, filed on an intent-to-use basis). We use the ™ symbol while the application is pending and will switch to ® if and when it registers.
DJs Golden Rule™
DJs Golden Rule™ is a trademark of Douglas Johnson. It names the memory-ownership rule that the project owner made binding for Tessero and Talario on October 24, 2026:
The layer that allocates the memory must own its deallocation.
The principle itself is rooted in established practice in native and PHP extension development, and anyone is free to follow it. The mark identifies how Tessero and Talario adopt and enforce it: every allocation is released only by the layer that made it (the C kernel, the Zend extension, the FFI binding, and native consumers that link the library), a run-time ownership check aborts on any foreign, double or wrong-size release in the test and sanitizer builds, and a static check in continuous integration keeps it that way. The full contract is the project's ADR 0015, “Memory ownership”.
The mark is not registered; we use the ™ symbol to claim it.
DRAFT: requires legal review before launch. This document is a working draft generated for review. It is not legal advice and is not final.
The name-usage policy below is a draft pending legal review.
- You may use the Tessero name to refer to the project truthfully, for example “built with Tessero” or “a Tessero plugin”.
- Please do not use the name or any future logo in a way that implies official status, endorsement, or affiliation without written permission.
- Do not use the name for a product or service that could be confused with the Tessero project.
Permission and questions
To request permission or ask about name and logo usage, contact [email protected].