Changing the licensing requirements

[frozolotl]

Description

Currently, a package must be licensed under a OSI-approved license to be considered for inclusion in the package repository.
This requirement seems unnecessarily strict for packages that are not purely made of source code.

As an example, the Citation Style Language repository is licensed under CC-BY-SA-3.0, which is not a OSI-approved license, but neither does it impose any unreasonable restrictions.

Therefore, I think we should perhaps change the requirements to also allow licenses matching the Open Definition 2.1.

There is also a case to be made to allow licenses restricting the use on certain kinds of groups. Take the Creative Commons NonCommercial licenses as an example.
I'm not sure, however, whether disallowing (the sharing of) derivatives entirely could be permissible, which is why I did not advocate for allowing all Creative Commons licenses.

[reknih]

We mainly imposed the OSI requirement because we want the software on Typst Universe to be Free and because they have compiled a list of free software licenses. I had a look at the Open Definition 2.1, and in its tagline, it says "[...] Open Data, Open Content and Open Knowledge." Opposed to the OSI licenses, it does not seem to be designed for software in particular. This is further supported by the fact that the domain column on their licenses page only ever contains the values "Content" and "Data". An argument can be made that arguments can consist of content or data primarily, but that is rare across what we see on Universe today.

Using non-software Open / Free / Libre licenses for software can create problems and is discouraged by, for example, Creative Commons themselves. This has even created problems for us in practice in the past.

For this reason, we will not change the rules to include all licenses matching Open Definition 2.1. However, we acknowledge that packages dealing with CSL styles derived from the official repo will want to license as CC-BY-SA 3.0. Although, according to their maintainer in the linked issue, they seem to interpret the "Share Alike" requirement broadly, he cannot speak on the behalf of all the repo's contributors. Because we don't want to expose package authors to the liability risks that come with relicensing CSL styles, we will allow CC-BY, CC-BY-SA, and CC0 licenses for compatibility reasons but discourage them in favor of true software licenses.

[kre9]

I had a question on the discord, which resulted in this issue being created.
Is this sufficient for marking this in the package?:

• typst.toml contains license = "0BSD AND CC-BY-SA-4.0"
• the README of the project repository clearly states, which licences apply to the files

[reknih]

Yes, with #1521 merged, it will be!