JOS is a small operating that I am working on as an independant study, JOS is a pretty monolithic kernel (basic commands and filesystems are compiled into the kernel) I do not believe this is the best approach, but this is my first real dive in to building an Operating System.
JOS is written completely in C (and a bit of assembly) at the moment but, I am looking to implement other languages into the code base where I see fit. It would be nice to have rust compatibility, C++ is already 'implemented' - that is if you have the whole i386-elf cross compiler collection - I just haven't found a use for it yet.