Ranked in these QuestionsQuestion Ranking
Pros
Pro Very customizable
It's more barebones than Linux so you can customize it every way you like.
Pro Not tied to systemd
Pro Clean design
Clang toolchain has a cleaner design than gcc, it's easier to implement a front-end to LLVM.
Cons
Con Linux can do pretty much everything it can, and better
Unless you're looking for some niche server functionality, it's pretty much certain that a linux distro already has whatever you want in a more efficient and easier to use form.
Con Server-oriented, good for developing back-end software and not much else
Con No systemd
Systemd makes it trivial to automatically start and manage programs, offering a whole lot more control than a cobbled together bundle of some archaic init system, cron and random bash scripts.