Updating the licence for the free edition of CPO

A potential customer wrote to ask whether the free edition of CPO could be used for commercial work. We never intended it to be, but after checking the licence we found there was no clause that said it could not be. The free version of CPO that they downloaded could still be used for commercial purposes.

What the licence said

Our end-user licence does two things. It states that CPO Ltd owns the copyright, and it disclaims any warranty that the software is free of errors. There is no grant-of-licence clause, and no restriction on what the software may be used for.

Everything else we have written about the free edition describes who it suits rather than what it permits. It is "ideal for students". It is for "exploring the functionality before purchasing". All of that is true, and none of it is a condition. We described our intentions for years without ever writing them into the licence.

Why it matters

The free edition is capable. It runs most of the benchmark and example files, and it gives accurate answers to a wide range of real problems. That was deliberate. The programs have been used for years to teach charged particle optics at Manchester, and a stripped-back version would be no use for that.

Capable and unrestricted together mean something we did not intend. A firm can do paid work in the free edition, bill a client for it, and be entirely within its rights. Licence sales are what pay for developing these programs and supporting the people who use them.

What changes

From the date of this post, the free edition licence says what we had always assumed it said. You may use it for learning and teaching, for academic and other non-profit research, and for trying the programs out to see how they work. You may not use it for commercial work, meaning any use that contributes to a product, a service or a result somebody pays for, or that is carried out for a customer, an employer or a client.

If you are evaluating CPO with a purchase in mind, the evaluation edition is built for that job: every option unlocked, full segment counts, fifteen days. The full text of both licences is on the licence page.

What is not changing

This is not retrospective. If you downloaded the free edition before the date of this post, you have it under the terms it came with. Nobody is being contacted about past use, and anyone who has used the free edition commercially was within the licence as it stood.

There is no new enforcement either. The free edition still needs no licence key, still runs with no internet connection, and we have not added a check of any kind. The change is a paragraph of text, and it works if people choose to respect it. In our experience most do.

Teaching and academic use are unaffected. Students, lecturers and non-profit researchers lose nothing. That is who the free edition has always been for.

If you are not sure

Write to us at [email protected].