[fulafel]

I'm sure they don't need my recommendation, and the whole thing is moot today if Rust has fixed the issues in the years since.

But to play with counterfactual history: Apparently Go is fairly big there. There was a Usenix paper about a Go kernel a while back, and there's also gVisor. Then there is Ada, and Kotlin native, and various safe dialects of C. MS did one in .NET - there were lots of options.

[staticassertion]

There are papers with Python kernels. Doesn't mean Python's a good language for writing a kernel. gVisor had to fight Go quite a lot, I think it was a huge mistake for them to choose it.

Ada is the only language you've mentioned that really fits IMO. One of the safe languages like P would be interesting but it's unproven in the space.

As for Ada, it's a sad story, but ultimately the language is unlikely to gain traction after too many early mistakes (particularly around licensing).

[fulafel]

Of course I now had to go dig up the reference due to the flippant Python kernel comparison :)

The benefits and costs of writing a POSIX kernel in a high-level language

Cody Cutler, M. Frans Kaashoek, Robert T. Morris MIT CSAIL

https://www.usenix.org/conference/osdi18/presentation/cutler

So its from quite a prestigious institution, has at least one big authors, and concludes that it works quite well and recommends it over C for new kernels and VMMs.

I also disagree the "no traction" argument about Ada since it's been used in real projects and had a big enough developer community for a long time, and is alive and well. People can surely pick up new programming languages when they join a new project, I know I've done it many times. Tooling licensing should be fine as well since GNAT is available under GPL + Licensing exception, same as Google has been using with GCC since dawn of time, and under the Adacore license which Google probably can afford.

So, I hold that there were many other options vs Rust. Including the others in my original comment that we didn't get to in details. Except Kotlin Native, I made a timeline mistake there, it was too early in 2016.