alt Hacker News> even if the reader hadn't heard of ETH Zurich it could be reasonably inferred that ETH Zurich is an academic institution, probably in Zurich, where Oberon was successful. Part of writing is trusting that the reader is a rational person
The first sentence of the README says, "This project modernizes the Kernel of Oberon System 3 (version 2.3.7) by migrating it from the original Oberon Boot Loader (OBL, written in assembler) to the Multiboot specification (handled in Oberon directly in the Kernel)."
Armed with that and the headline "Oberon System 3 runs natively on Raspberry Pi 3", it can be reasonably inferred that "Oberon System 3" is an operating system (shown here of being capable of running on a Raspberry Pi). It doesn't require prior familiarity with Oberon, despite what the previous commenter said.
Neither you nor the original questioner are being particularly rational about this.
> it can be reasonably inferred that "Oberon System 3" is an operating system
"Oberon is an operating system" was indeed evident, but it's also not particularly illuminating. There are dozens of niche operating systems, why do we care about this one in particular? What does it do that other operating systems don't?