Terms

What you are getting

Two analysis tools that run in your browser, free to use in full. Every model, every statistic and every confidence interval is available without paying, and figures can be exported at publication resolution. Free exports carry one small grey credit line along the bottom edge.

A one-time Pro licence removes that line. It is a purchase, not a subscription: there is no renewal, no seat count and no expiry date in the key. Payments are not yet switched on — until they are, the licence cannot be bought, and the pricing page says so rather than showing a button that does nothing.

What the licence lets you do

Use the software, for any purpose, commercial or academic, on as many of your own machines and browsers as you like. There is no seat limit because there is nothing to count — the licence is a signed string, not a registration.

Figures you produce are yours. There is no claim on them, no attribution requirement on a Pro export, and no restriction on publishing, licensing or selling them. The credit line on a free export is a request rendered into the file, and removing it by hand is not something anybody is going to come after you for — buying a licence is simply the easier way to do it and is what keeps the tools free for people who cannot.

Do not resell the licence key or redistribute it as a way of giving other people paid access. That is the one thing it is not for.

Refunds

If the licence does not do what this page says it does, or you bought it by mistake, write to the address in the footer and you will get your money back. There is no time limit and no form to fill in. This is affordable to promise precisely because the tools are fully usable before purchase — nobody is buying blind, so nobody should need to argue about it.

What this software does not promise

The methods are documented and the results are checked against published worked examples and certified reference values, and the checks run automatically on every change. That is a real basis for confidence and it is not a guarantee of correctness. Software has bugs; statistics has assumptions that data violates; and no test suite proves the absence of either.

You are responsible for the numbers you publish. Read the caveats on the methods page — they are there because they matter, not for form’s sake — and satisfy yourself that the model you chose suits your data. If something looks wrong, please report it; a reproducible bug in the arithmetic is the most valuable thing anybody can send.

To the extent the law allows, the software is provided as is, without warranty, and liability is limited to what you paid for the licence.

Governing terms

These terms are written in plain English on purpose, and where a plain reading and a lawyerly one differ, the plain one is what was meant. If a court finds part of them unenforceable, the rest still stands.