licensing Model of CodeAster vs Simscale

rodrigofarias

Hi everyone,

I’d like to discuss an "issue" I’ve encountered with SimScale offering. As many of you know, SimScale relies on Code Aster under the hood, which is licensed under GPL 3.0. Under GPL 3.0, any service or product that distributes a modified version of Code Aster (or incorporates it into a larger work) must make the complete corresponding source code available under the same license terms.

However, despite leveraging Code Aster in their backend, SimScale does not publish (as far as I know) their modified source or installation scripts. This appears to conflict with GPL 3.0 provisions:

Source-code availability: Distributors of GPL-licensed binaries must offer the “preferred form for modification,” i.e. the full source code of any changes.
Copyleft reciprocity: Any derivative work combining GPL code with proprietary software must itself be released under GPL 3.0 when distributed.
No additional restrictions: You cannot add terms that limit the recipient’s GPL freedoms, such as withholding code.

I have contacted SimScale a few times in the past requesting clarification about this, but I received no response. I have nothing against SimScale, I’m simply trying to understand their business model, as I myself have an idea for a software product using Code Aster as its backend.

Superficially, it seems there are two possibilities: either SimScale use of Code Aster somehow avoids “distribution” under GPL 3.0 (maybe by keeping all processing entirely server-side), or they’re inadvertently in violation. If it’s the former, a clear statement from SimScale explaining how they comply, or why GPL does not apply to their deployment model, would be very helpful. If it’s the latter, I’d encourage the community to request EDF to address this issue.

Im posting this here since they never answered me, and I know that Simscale employees come to this forum regularly.

Has anyone here heard an official response from SimScale on this licensing question? Are there precedents for GPL-compliant cloud offerings that could clarify the obligations? Any pointers or experiences would be greatly appreciated.
I think any info would be helpfull for people who intend to develop additional solutions based in Code Aster.

Thanks!

AsterO'dactyle

Hello,
From my point of view, they are well in line with the GPL license, since the version they use is not modified. As far as I know, they use the same version.
As far as installation is concerned, I think we're on the borderline of software rights, it's a bit of a grey area from this point of view.
Generally speaking, the use of open source solutions in "cloud" mode remains a legal framework which, as far as I know, has not been dealt with. I don't know if there are examples in fields other than computation software.

rodrigofarias

AsterO'dactyle

thanks for the pointer on the SaaS loophole. Currently there is the GNU Affero General Public License (Affero GPL ou AGPL), that closes the loophole.
If possible, I have two related questions:

Commercial use without modification
If I deploy an unmodified Code_Aster binary entirely on my own servers (users only receive simulation outputs via web/API), am I free to offer that as a proprietary, commercial service without releasing any source? Its that what Simscale does, right?
Local client-side deployment
Alternatively, is there any way to ship Code_Aster as a downloadable package or desktop app that runs on the user’s PC—without triggering GPLv3’s “distribution” requirements beyond providing the standard GPL-licensed source? In other words, can I offer clients a local solver they install themselves, while still keeping any surrounding UI or tooling proprietary?

And I still would like to rear something from someone from Simscale.

Fab@simvia

Dear Rodrigofarias,

As you noted, the AGPL license was designed by the FSF to address the so-called "SaaS loophole".

Since Code_Aster is released under GPLv3 (not AGPL), you are indeed allowed to build a SaaS product on top of it, including modified versions, without being required to distribute your source code, as long as you do not distribute the binaries or source outside your organization. This is the model used by SimScale and other cloud platforms.

Regarding your second question about local client-side deployment: the situation changes. If you distribute software (even partially) to someone outside your organization, the distribution clause of GPLv3 applies. In that case, you must provide the full corresponding source code to the recipient, but not to the public at large. This is an often misunderstood point: only the entity receiving the software can request the source, not everyone.

One more legal-technical point worth mentioning: you can interface GPL software with proprietary components as long as you don't create a "derivative work" through tight coupling. The FSF considers dynamic linking, RPC calls, API usage, or writing .comm files (in Code_Aster’s case) to be interfacing, not integrating. So for example, building a proprietary GUI or launcher that invokes Code_Aster and parses its outputs does not violate the license.

I hope this helps clarify things.

Fabien

rodrigofarias

Fab@simvia

Thank you very much Fabien!

"In that case, you must provide the full corresponding source code to the recipient, but not to the public at large. This is an often misunderstood point:"
So, in theory, I could commercially offer my proprietary GUI with the original Code_Aster as the backend, and include a contractual clause preventing the recipient from redistributing (what I’ve provided) for free?

Another question:
"So for example, building a proprietary GUI or launcher that invokes Code_Aster and parses its outputs does not violate the license."
Does this mean I could sell my GUI packaged with Code_Aster, while keeping my .comm files, preprocessing scripts, and other proprietary routines embedded in the GUI hidden from the user? In other words, the customer would get the GPL-covered Code_Aster source (as required), but my proprietary automation logic could remain closed-source?

Again, many thanks for your thorough explanations!

k_zurawski

rodrigofarias
or you may prepare and sell pre/post and point to code-aster site to download solver.

If you're thinking of writing your own pre/post for c_a, don't think, just write. I'll be your first customer.