“*nix” means a Unix-like OS just generally (http://en.wikipedia.org/wiki/%2Anix), like for example in “Minix” and “Xenix”. Sticking “OS” to the end of an OS name is also commonplace. However, the title on the page is “The Learnix Operating System”, so the actual name seems to be just “Learnix”.

It’s arguably Nix and NixOS who have unnecessarily stepped into the “*nix” namespace without adding a distinguishing prefix.