Some code snippets here: https://nova-lang.net/introduction-to-nova/sight/

EDIT: seems to be open source, just isn't mentioned on the website https://forge.nouveau.community/nova

Where did you get this? Of the three implementations I see here all three have available sources, Myte and Serpens don't have licenses, and Pyra has an Unlicense open-source license.

https://nova-lang.net/implementations/

Their forgejo instance has an interpreter in go https://forge.nouveau.community/nova/ni