[talex5]

It depends on which lightweight OS and which unikernel. But e.g. a stripped down Linux will still have a huge amount of C. If you're going to write your kernel in something safer, then you might as well make a unikernel, rather than creating a kernel/userspace split.

It's hard to see how you'd get a traditional OS stripped down anywhere close to e.g. the mirage-firewall unikernel (http://roscidus.com/blog/blog/2016/01/01/a-unikernel-firewal...)

[EvanPlaice]

Not necessarily.

NodeOS cut out everything but the absolutely essential parts of the linux kernel. No c libraries, no c compiler, no POSIX utilities, no user space, etc.

Instead, everything runs on V8 (ie which also takes care of sandboxing) and minimal tools were rewritten in pure javascript, incl a git clone tool.

It's amazing how much you can cut out and still have a decent platform to build servers.

[willtim]

What's next PythonOS, RubyOS? Just learn OCaml, its really not that hard.

[lmm]

You're still running the linux scheduler in C, and you're still context switching for system calls. And can you run your whole stack as a user-mode program by changing one line in the build file the way you can with Mirage?