http://joeduffyblog.com/2015/12/19/safe-native-code/ and the rest of that blog on Microsoft Research's Midori research OS, based on C# and type safety rather than traditional process-based (i.e. Memory Mapping Unit-based) security
https://sel4.systems/ for a proven-secure (with many asterisks) native-code microkernel
MirageOS (OCaml) and similar (often Rust-based) unikernels
... and of course, the rise of the heavyweight microkernel under the name "hypervisor"
Each of these ideas has very serious downsides, but each also has earnest proponents.
http://danluu.com/clwb-pcommit/ on the speed of modern persistent storage and the need to get the OS out of the way for best performance
http://blog.erratasec.com/2013/02/custom-stack-it-goes-to-11... on the speed of modern networking and the need to get the OS out of the way for best performance
http://joeduffyblog.com/2015/12/19/safe-native-code/ and the rest of that blog on Microsoft Research's Midori research OS, based on C# and type safety rather than traditional process-based (i.e. Memory Mapping Unit-based) security
https://sel4.systems/ for a proven-secure (with many asterisks) native-code microkernel
MirageOS (OCaml) and similar (often Rust-based) unikernels
... and of course, the rise of the heavyweight microkernel under the name "hypervisor"
Each of these ideas has very serious downsides, but each also has earnest proponents.