If you spend time reading the article, you can agree or disagree with his choices, but he provides several reasons for why he chose to rewrite in Rust over after the initial project was written in C:

"At that moment, I decided to switch to Rust (my first project in this language), which represented several advantages:

- Restart the project from the beginning, using lessons learned from previous mistakes

- Be a bit more innovative than just writing a Linux-like kernel in C. After all, just use Linux at that point

- Use the safety of the Rust language to leverage some difficulty of kernel programming. Using Rust’s typing system allows to shift some responsibility over memory safety from the programmer to the compiler."

Unfortunately, your comment doesn't add anything to the conversation and distracts from the interesting project being presented.

It's not trying to replace the Linux kernel though, it's a personal project trying to be compatible with it. Yes, they're asking if anyone else wants to join near the end, but that doesn't imply anything. Small-scale hobbyist projects with fellow enthusiasts exist.

These comments seem a little unfair. This is a project started for fun by a student in his spare time trying to learn how to develop an OS. He may very well have been a teenager when he started this and likely chose an MIT license because the Github wizard gives you it as a default if you have no preference or know nothing about licensing, which is likely to be true for most students.

Given his explanation, it seems he switched to writing in Rust largely because it allowed this project to do double duty allowing him to learn Rust while learning to develop an OS. That is an entirely reasonable thing to do. The thing with Linux compatibility isn't explained, but most likely because it makes the process much simpler if you can run at least some existing software as-is and not have to write an entire userspace yourself to be able to actually do anything with your toy kernel. Wholesale new OS projects ultimately intended for real-world use by people other than the developer don't seem to be taking that approach.

That's pure FUD.