Licence

1. The licence

DCTL is not released under a bespoke licence. It uses an off-the-shelf licence from the PolyForm Project — short, plainly written, and identical for everyone:

PolyForm Noncommercial License 1.0.0

That linked text is the licence, and it is published verbatim as LICENSE.md in the repository. This page explains it; where the two differ, the licence text governs.

2. What counts as a permitted purpose

Any noncommercial purpose is a permitted purpose. The licence spells out two categories in particular.

Personal uses

Personal use for research, experiment and testing for the benefit of public knowledge, personal study, private entertainment, hobby projects, amateur pursuits, or religious observance — without any anticipated commercial application — is permitted.

Backing up your own photo library, running a homelab, archiving your own film work, learning how the format works: all fine, and free forever.

Noncommercial organisations

Use by any of the following is permitted, and this is written into the licence:

• charitable organisations
• educational institutions
• public research organisations
• public safety or health organisations
• environmental protection organisations
• government institutions

Crucially, this holds regardless of the source of funding or obligations resulting from that funding. A publicly funded university, a grant-funded research group or a state health service does not need to buy anything.

3. Business use needs a commercial licence

Any use by or for a business is outside the licence — including a sole trader backing up client deliverables, and including a proof of concept.

There is no built-in trial period. The licence grants no evaluation window, so a company cannot lawfully trial DCTL under it. We issue evaluation licences on request and would far rather you tested DCTL properly against real data and real providers than skipped the exercise. Email [email protected] and ask.

4. What the licence allows

For any permitted purpose, the licence grants you:

• a copyright licence to use the software;
• a distribution licence — you may distribute copies, including with your changes;
• a licence to make changes and new works based on it;
• a patent licence covering patent claims the licensor can license that you would infringe by using the software.

Your “fair use” rights under law are untouched by these terms.

5. Notices

If you distribute any part of DCTL, you must ensure whoever receives it also gets a copy of the licence terms — or the URL for them — along with the plain-text Required Notice: lines supplied with the software.

6. Getting it wrong

The first time you are notified in writing of a violation, your licences continue if you come into full compliance and take practical steps to correct past violations within 32 days of receiving notice. Otherwise they end immediately.

If a personal project turns into a business, that is a good problem to have. Get in touch and we will sort the paperwork out — we are not looking to catch anyone out.

7. Patent defence

If you make a written claim that DCTL infringes or contributes to infringement of any patent, your patent licence ends immediately. If your company makes such a claim, your patent licence ends for work on behalf of your company.

8. What this licence is not

PolyForm Noncommercial is source-available, not open source. It is not OSI-approved, because it restricts who may use the software and for what. If your organisation has a policy permitting only OSI-approved licences, DCTL will not satisfy it without a separate commercial agreement.

We would rather state that plainly here than have it surface late in a procurement review.

9. Your data remains yours

KONG GROUP LLC claims no ownership of, and receives no access to, any data you process with DCTL. DCTL performs no telemetry, sends no usage analytics, and requires no account, licence key or activation to run — nothing about the licence is technically enforced.

Vaults use a design-frozen, publicly specified format, and a dependency-free C99 reference decoder is published alongside it. A licence lapsing, or a dispute, never makes your stored data unreadable. That is the point of the twenty-year restorability principle.

10. Pre-release status

DCTL is pre-1.0. Parts of it are complete and exercised; parts are not. The status table on this site and the project’s own status document describe the real state of the code. Keep independent copies of anything you cannot afford to lose.

11. No warranty, no liability

As far as the law allows, the software comes as is, without any warranty or condition, and the licensor will not be liable to you for any damages arising out of these terms or the use or nature of the software, under any kind of legal claim.

A negotiated commercial agreement may vary this. The standard licence does not.

12. Contact

Licensing questions, commercial licences and evaluation licences: [email protected].