Terms and software licence.

Who you're buying from

Inverse Square ("we", "us") is an independent software studio in the United Kingdom. Our online store is run by Lemon Squeezy, which acts as our reseller and merchant of record. When you buy, your contract of sale is with Lemon Squeezy and their buyer terms apply to the payment. These terms cover the software itself and your licence to use it.

Your licence

• Perpetual. A licence is a one-off purchase, not a subscription. The version you bought keeps working for as long as you want to use it.
• Updates. Updates and fixes within the same major version (for example 1.0 to 1.9) are included. A new major version may be a paid upgrade, and we'll offer existing owners a discount when there is one.
• Devices. Each licence key can be active on the number of computers shown on the product page at the time you buy. You can deactivate a computer to move the licence to another one.
• Personal and commercial use. Unless the product page says otherwise, you can use the software for paid work, and you own everything you make with it.
• Who it's for. A licence is for one person, or for one seat in a business. Don't share, resell or publish your key.

Licence activation

When you first enter your key, the app checks it with Lemon Squeezy's licence service and registers that computer. It may check again now and then. After activation the software keeps working offline, and we'll never switch off a licence you've paid for, except for a key that was refunded, charged back or obtained fraudulently.

What you agree not to do

• Bypass or remove the licence check, or share a cracked copy.
• Reverse engineer the software, except where the law allows it.
• Use the software to break the law or someone else's rights.

Open-source parts of our software, such as the Strength Check build of OrcaSlicer, are covered by their own open-source licences, and nothing here limits your rights under those.

Early access and betas

Early access and beta builds are work in progress. They may have bugs, change or lose features, and we may ask for feedback. Don't rely on them for critical work without keeping your own copies of your files.

Engineering results

Simulation, strength and design tools give estimates from models and the inputs you give them. They help you make decisions, but they don't replace testing, professional sign-off or the safety factors your work calls for. Check anything that matters before you rely on it.

Support

Support is by email from the people who build the software. We aim to reply within two working days. Write to hello@inversesquare.app or use the contact form.

Free Labs tools

The Labs tools on this site are free to use, with no account. They're provided as they are, and while we try to keep their data accurate, prices, specifications and availability can change, so check with the retailer before you buy. Some Labs pages contain affiliate links: if you buy through one we may earn a commission, at no extra cost to you.

Our responsibility to you

If you buy as a consumer in the UK, you have legal rights that these terms don't take away, including the right to software that is as described, of satisfactory quality and fit for purpose. Otherwise, as far as the law allows, we aren't liable for indirect losses such as lost profits or lost data, and our total liability for a product is limited to the price you paid for it. Nothing here limits liability for death or personal injury caused by negligence, or for fraud.

Changes and law

We may update these terms, and we'll change the date at the top when we do. The terms that applied when you bought a licence keep applying to that licence. These terms are governed by the law of England and Wales, and if you live elsewhere in the UK you can also bring a claim in your local courts.