In case you're still checking these comments: do you think FlingOS is a good fit for someone who is comfortable with C, or would they be better off with something like xv6?
Our articles and videos are largely language independent so still contain a lot of very valuable information for any OS developer, irrespective of language. I would say our codebase is useful for seeing how to make the various drivers work but that someone comfortable in C ought to develop in C and simply refer to our code when/if they get stuck.