I’ve been using both, Qubes OS and Sculpt lately, and have been quite satisfied with both of them in many ways. However, there are a number of drawbacks in each that could be overcome if their strengths were combined.
Regarding Qubes OS, some of the biggest negative aspects are the large codebase in Xen and the complexity of Dom0, the need for virtualization with the associated overhead of running kernel and underlying operating systems in each VM (to perhaps run a single application), the problem of managing memory efficiently due to the need to rely on VMs to indicate memory pressure and prioritize somehow who gets what, the inefficient use of disk cache across VMs, etc. None of these are showstoppers and can be worked around (add memory, buy a faster CPU) or just taken as a (blue) pill you need to swallow as a counterbalance to all the significant benefits that you get with Qubes OS.
Scult OS (based on the Genode OS Framework) on the other hand, provides a capabilities based system with hardware isolation using memory segmentation/sandboxing, managed by a microkernel, with the ability to easily port linux applications and/or run VMs (it can even run a port of Virtualbox or Nova VMMs for easy execution of native operating systems). Sculpt OS is lien, fast and secure. The disadvantages are a small development community, relatively slow progress and a management/configuration system that is still quite clunky.
Has anyone considered a possible Qubes OS port that could leverage the underpinnings of Genode to replace Xen and eliminate the need for virtualization just to provide isolation? I believe that it could create a better/faster Qubes OS but, of course, at a price of a pretty significant porting effort.
What do you think?