ILIOS
- InterLink Internet Operating System, single tasking, uses interrupts for processing, for routers only and maximum throughput on i386+ systems; but in tests it barely beat NetBSD on same hardware, so author stopped work. Has fast IPv4 stack, based on XeOS
- http://www.rink.nu/trac/ilios/

x-kernel
- Object-based framework to implement network protocols; defines an interface that protocols use to invoke operations on one another (i.e., to send messages to and receive messages from adjacent protocols) and a set of libraries to manipulate messages, part
- http://www.cs.arizona.edu/xkernel/

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