It's been done in the past. OS's come to dominate mostly for marketing rather than technical reasons. Much like startups. Integration with legacy systems and ra

It's been done in the past. OS's come to dominate mostly for marketing rather than technical reasons. Much like startups. Integration with legacy systems and rapid development increase chance they'll get uptake. The existing stuff is mostly C, C++, etc. So, the new stuff that dominates tends to reuse that. Redoing it all in a safe language will be a lot of work. That's why high-assurance security has focused on redoing the smallest, most-trusted parts of the stack or working on transformations of legacy code like Softbound+CETS or CHERI CPU that address root problems. Although I doubt we'll see a big one, there's already smaller projects that do useful stuff with safer languages. ExpressOS comes to mind given the kernel is C# and Dafny running Android apps that are Java. The L4 kernel and Linux remain in the system with L4 replaceable by safe stuff like Muen in SPARK language. Replacing Linux will be a lot harder. ;) However, if wanting mobile or other apps that aren't Android compatible, one might be able to use work like Redox, JX, or Oberon to eliminate unsafe language entirely. https://haohuim.appspot.com/static/pubs/expressos-asplos13-slides.pdf https://haohuim.appspot.com/static/pubs/expressos-asplos13-s... Another in alternative OS's is A2 Bluebottle from Wirth's people at ETH written in an Oberon dialect. Main Oberon OS is designed for simplicity and teaching. A2 is a batteries-included OS with a GUI designed to be useful. When I tried it, it ran snappy fast with networking, editor, compiler, and so on. Very minimal given only a few students worked on it but it is usable and extendable. Below was first link I found in Google so I haven't vetted it. https://github.com/Ignat99/a2 https://github.com/Ignat99/a2 Redox OS in Rust can do a lot currently. They plan to expand it more. Already has a GUI, shell, networking, and the standard library of Rust. http://redox-os.org/ http://redox-os.org/