Unikernels are essentially the far less interesting cousin of exokernels, in that they nominally preserve the libOS angle but are limited to application deploym

Unikernels are essentially the far less interesting cousin of exokernels, in that they nominally preserve the libOS angle but are limited to application deployment under a bare-metal hypervisor. Much of the motivation for microkernel research, too, was for applications to be able to control their workloads at a finer granularity while retaining a full OS environment. Scout and SPIN were such examples. Something as simple as making page replacement and eviction a userland server where each library or application can implement its own policy over the RPC interface, can yield great benefits.