How hard would it be to take one operating system kernel and integrate features from other kernels into it?
>>61360919
As easy as installing gentoo.
If you only listened to Stallman and developed HURD instead of L*nux it would've been dead easy because in HURD every part of it is it's own separate server/daemon running in userspace talking to other server/daemons via a standardized communication protocol.
>>61360997
That sounds slow as fuck
>>61360997
Which results in terrible fucking performance. There's a reason Apple piled a bunch of shit onto mach instead of running it in userspace.
>>61360919
If by "integrating features" you mean the concept of the feature itself, it's entirely dependant on what said feature is. Writing kernels is hard work, and there is very little room for error.
>>61360919
very doable with previous experience making kernels, spend some time on xda and make a custom kernel for your ((android)) phone to learnt
>>61360919
Depends on how close the code bases are to each other, as well as the modularity and specification/documentation of the kernel
>>61360919
Depends if they have different licenses. cf zfs