SimScale CAE Forum

GPL License Simscale


Hi Every one, I have a question for those who can help me. I read that simscale uses openfoam and code_aster under the hood and both of them are GPL license open source software. According to GPL license any software uses GPL software must also be GPL which means that simscale should provide the source. So does this mean that any one can get the source code of simscale?


Hi @Mkhairy

Great question! It’s true that SimScale is using OpenFOAM and Code_Aster which are licensed under the GPL. It’s also not an easy one - software licenses are sometimes written in a form which makes them quite hard to read and understand. The question you’re asking is coming up from time to time, so I think it’s useful to share some more information.

The main point is that the event which triggers the GPL is distribution. Anyone who distributes software that contains GPL licensed code is forced to publish the source code alongside.

Allowing people to use GPL software (such as OpenFOAM) over the network is however not considered as distribution of the software and therefore doesn’t fall under the “viral” terms of the GPL.

(As a little sidebar: there is a different version of the GPL, called the AGPL, which also applies when an application can be accessed via the network. This license does not apply to OpenFOAM and Code_Aster, though.)

The difference between distribution of software (which is where the GPL does apply) and allowing people to use software via the network (where the GPL does not apply) is the reason why SimScale is not required to publish the source code.

I hope that I was able to answer your question. Feel free to ask if something isn’t clear.