[steego]

While I wouldn’t recommend it, it wouldn’t be that crazy as there’s an experimental F# to Rust compiler that’s part of the Fable compiler.

[anta40]

Perhaps the closest thing: https://github.com/CosmosOS/Cosmos

[NikkiA]

I think MSRL had a F# based OS they were playing with around the same time as Midori and Singularity.