Every one of the 117 treatises carries the line Licence: CC BY 4.0 in its own header, and every treatise page on this site declares the same licence in its machine-readable metadata. The licence covers the text of the treatises together with the tables, equations and figures Eigenia made for them. The whole set is listed at the treatise index.

You may copy a treatise and pass it on, in any medium and any format. You may translate it, excerpt it, rewrite it, teach from it, feed it into something else and publish the result. You may do all of that commercially. You do not have to ask, and once you have the permission it cannot be taken back from you.

Give credit. In practice that is three things: name the author and the work, link to the licence so that the next reader knows their own rights, and say whether you changed anything. The credit goes wherever is reasonable for the medium you are working in, so a footnote, a slide, a caption and a line in a README all count.

This is the attribution Eigenia asks for. Replace the title, the address and the date with the treatise you actually used.

Filled in, for one of the papers in the digital twin working group:

If you changed the work, say so in the same place. A line beginning adapted from, or translated from, does the whole job.

Attribution is not endorsement. Naming Eigenia as the source of something you built on does not mean Eigenia has seen your work, agrees with it, or stands behind it, and you are asked not to suggest that it does. Where your version differs from the original, saying so protects both of us.

You may not attach legal terms or technical measures to a copy that stop the next person doing what the licence allows. Putting a treatise behind a paywall of your own is permitted; putting it behind one and telling your readers they may not redistribute it is not.

It covers the treatises. It does not cover this site's source code, its design and interface work, or the name Eigenia. Nor does it cover material that Eigenia quoted or reproduced from somewhere else inside a treatise, which stays under its own terms. The citations in each paper are there so that you can find those terms.

This page is a summary written for readers. It is not the licence. The licence text is published by Creative Commons, and that text is what actually governs. Where this page and that text disagree, that text wins.

It is published at https://creativecommons.org/licenses/by/4.0/

If a use you have in mind is not obviously covered, write and ask. An answer is quicker than a guess, and it is free.