Copyright World3 Model

[richard__]

Dear Vensim team/community,

Some colleagues and I are currently using Vensim PLE as part of a research project in our Master's program. We have a few questions regarding copyright, specifically related to publishing a paper that includes a modified version of the World3 model.
Our main concern is about the World3 model that comes bundled with the software. What are the copyright terms for this model? We have extended it by incorporating renewable energy and circular economy, and we would like to publish the modified .mdl file as an appendix to our academic paper.
Would this be permissible under the current licensing terms of Vensim PLE and the World3 model?
Also some indication for how to reference the model in our article would be appreciated.

Thank you in advance for your clarification!
Best regards,
Richard

[Administrator]

We should probably add a licence to the models that we developed and ship with Vensim. I'll get onto that.

The world model, I think it's safe to assume that it is in the public domain so you can extend it as you wish.

[tomfid]

I think you are certainly safe to extend and adapt World3 however you wish. Obviously it would be a courtesy to cite the original authors, whether or not it's strictly a legal obligation - which I'm sure you would.

The Vensim license only applies to Vensim and ancillary components - anything you create with Vensim is yours.