Overview
The Dual Interest Software License (DISL) is a software license that exists at the convergence of interests between developers and users in the self-hosted software space.
The license attempts to address the interests of both parties by promoting transparency and longevity.
Who is This For?
If you are a developer or an organization that wants to publish code for users to fork, modify, and redistribute, while also protecting the license key functionality in your software, then DISL might be for you.
Or, if you are a user who cares about auditing the code that you run on your hardware, then projects that use DISL might be of interest to you.
Protecting Users
"Users" means end users, and also developers who write code that depends on the project using DISL.
DISL protects the interests of users by allowing forking, modification, and redistribution of the source code, as long as the license key functionality is left intact. This means that access to the source code cannot be revoked from anyone who depends on it. It means that businesses can build on top of software that uses DISL and not have to worry about a rug-pull type situation.
Protecting Publishers
"Publishers" means the people who write and maintain the code.
DISL protects publishers by ensuring that their paid services remain accessible in redistributions of their software, allowing for their source code to exist in a public space where it can be reshaped organically, but with protections that guard license key functionality. This allows for the publisher to benefit from re-distribution, giving them the ability to continue to maintain the software without undue extra burden.
Openness Diagram
DISL is a source-available software license. The diagram below shows where DISL lands when compared in terms of openness against other common software licenses.
MIT Apache 2.0 GPL v2 DISL ELv2 ... Proprietary
│ │ │ │ │ │ │
───┴──────────┴────────────┴────────┴───────┴───────┴──────────┴─────
◄────── more free ──────┤────── more restricted ──────►
Do's and Don'ts
Here are a few examples of what you can and cannot do to software that is licensed under DISL. Essentially, if it's a paid feature, you cannot modify it in your redistribution.
| You can | You can't |
|---|---|
| Read, fork, and modify the source | Patch out a license-key check to unlock paid features |
| Self-host it, or host it as a service for your customers | Strip or hide the publisher's copyright and license notices |
| Sell support, consulting, or integrations around it | Distribute modified copies without prominently noting your changes |
| Build commercial products on top of it | Repackage and re-license it under different terms |
| Audit every line of code that runs on your infrastructure | Sue the publisher for patent infringement and keep your patent grant |
Attribution
DISL is an exact copy of ELv2 with one change: the limitation on providing the software as a hosted or managed service has been removed. This is what distinguishes DISL, making it well suited for software intended to be hosted by others, whether by users directly or by third party hosting providers.
Elastic License 2.0 is published by Elasticsearch B.V.; dualinterestlicense.com is not affiliated with or endorsed by Elasticsearch B.V. in any way.