Consider EUPL 1.2 as default license to restore OSI Open Source status

[BrycensRanch]

Proposal: Consider EUPL 1.2 as default license to restore OSI Open Source status while offering paid Apache License v2 licenses for corporations

Hey James and the SixLabors team,

First and foremost, I have read through some of the previous GitHub issues and conversations around the Six Labors Split License and the OG dual licensing with AGPL v3, which also alienated permissive OSS writers, and I entirely understand your frustration. It's really irritating to accomplish world-class work like ImageSharp, only to have individuals and organizations profit from your labor and pay you less than you're worth. I understand the initial aim of the split license was to drive business firms with yearly sales of more than $1 million to pay their fair share, which makes perfect sense.

I propose an alternative approach that keeps your $1M+ revenue threshold strategy intact while addressing a major friction point for open-source maintainers like me. I want to package and distribute my own OSS software in ecosystems that strictly require every single dependency to be fully OSI-approved or FSF-approved. Because the current Split License has the $1M revenue restriction baked directly into the terms, it technically violates the Open Source Definition (OSD) against discriminating against fields of endeavor.

What if SixLabors considered switching the default library license to the European Union Public Licence (EUPL 1.2), while continuing to sell Apache v2 / commercial exceptions on your pricing page?

Here is why this specific license achieves both of your goals better than AGPL or dual-licensing:

1. It is fully OSI and FSF Approved (You can call ImageSharp Open Source again)

Because the EUPL 1.2 is officially recognized by the OSI, ImageSharp would instantly regain its official "Open Source" status. Sure, it cannot rejoin the .NET Foundation because it requires permissive licenses, but that's their loss.

2. It is perfectly safe for permissive OSS users

Unlike the AGPL (which is virally copyleft and alienates MIT/Apache developers), the EUPL 1.2 is a weak/file-level copyleft license. More importantly, it has a built-in "Compatibility Matrix" in Section 5. This legally allows permissive open-source authors to link to it or even distribute combined works under other licenses without accidentally contaminating their own MIT/Apache codebases. OSS users will have zero friction. It is the license Pi-hole uses.

3. It will be flagged by corporate legal departments

While permissive OSS developers can easily navigate the compatibility matrix, corporate Open Source Program Offices (OSPOs) and legal departments despise copyleft.

• It contains a network/SaaS clause (meaning cloud deployment triggers obligations).
• It was drafted around European jurisdiction and is proven in the EU.
• Legal departments are typically concerned about copyleft virality, even at the file level, because they don't trust their engineers not to mistakenly edit it or statically link it in a way that would result in an audit nightmare.

Funnel to the Pricing Page

Corporate risk frameworks will consider EUPL 1.2 as a "time bomb" for their proprietary code; thus, they will not even attempt to read the "just don't modify it" loophole. They will naturally require their engineering teams to obtain a specific commercial exemption.

When a developer enters the ImageSharp website, they will notice that it now again states "Open Source". However, the pricing page will remain immediately adjacent. You continue to effectively prevent $1M+ businesses from freeloading since their own attorneys will compel them to purchase your commercial license out of fear of the EUPL's copyleft terms.

Things not mentioned

The build-time license checks. The EUPL 1.2 doesn't seem to have any comment on any license checks or DRM. However OSI does. It’s not allowed.

I know this proposal will be denied without doubt, but I’m just so bummed I can’t use it in my application anymore without relying on an ancient version or placing a native dependency on a library that wasn’t made in C#.

Thanks for everything you do.

[JimBobSquarePants]

Thanks for the suggestion, but I have no interest in pursuing this.

The proposed model fundamentally misunderstands what the current licensing model is designed to achieve.

Today the position is deliberately simple: qualifying users and organisations can use ImageSharp under the Six Labors Split License without paying, while commercial organisations above the revenue threshold require a commercial license. That commercial license is backed by a license key and build-time enforcement. The obligation is explicit, deterministic and enforceable.

Replacing that with EUPL would throw that away.

A large commercial organisation would then have a perfectly valid free licensing route. The commercial model would effectively become “use EUPL for free, or pay us if your lawyers dislike EUPL”. I have absolutely no intention of replacing an enforceable commercial licensing model with the hope that corporate legal departments will voluntarily pay because they are uncomfortable with copyleft.

The suggestion that this would somehow preserve the existing commercial model because corporate attorneys would compel companies to purchase a commercial license “out of fear” illustrates the problem particularly well. Fear is not enforcement. A license key is.

It would also create an absurd incentive for exactly the organisations the commercial license is intended for. Large organisations are generally the organisations best equipped to assess and comply with OSS licensing obligations. If they determine that EUPL is acceptable for their use, Six Labors gets nothing.

The current license is intentionally not OSI-approved. OSI’s definition does not permit the commercial distinction that the Six Labors license deliberately makes. That is not an oversight or a problem I am attempting to solve.

Likewise, the Community License already provides a free route for qualifying open-source projects. If an organisation has adopted an internal policy that every dependency must use an OSI-approved license, that is their policy. Six Labors is not going to redesign its licensing and commercial model to accommodate it.

The current model exists because maintaining software of this scale requires sustainable funding. It provides extremely broad free access while requiring economically significant commercial users to contribute to that sustainability.

EUPL dual licensing would weaken that model rather than improve it, so this isn’t something I will consider.