Exactly, was going to say the same thing. If you have a microkernel, your TCP stack will be in user space and can be more of a framework where applications can

Exactly, was going to say the same thing. If you have a microkernel, your TCP stack will be in user space and can be more of a framework where applications can be a lot more flexible in how they use it. With the right library structure you could even have custom OSI layers while reusing the rest. This would certainly be less buggy and of higher quality than everyone rewriting it wholly. In that sense, I'm glad we have efforts to reuse seL4 for general purpose operating systems, because it also has a capability system.