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
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.