[wisenull]

Rosetta Code is hosted on Miraheze. By clicking on Terms of Use at the bottom of any page you can see that the default for any wiki hosted by them is Creative Commons Attribution-ShareAlike 4.0 License: https://meta.miraheze.org/wiki/Terms_of_Use

[snvzz]

CC-BY-SA would already be excessively restrictive for what are quite straightforward implementations of basic algorithms.

But, literally the next string in that ToS:

>Wiki owners can change this

And they did. To FDL 1.2, a much less friendly license, in practice unusable.