Hi Royce, The systems we've built so far have been described completely at build time: there's no need for sevice discovery because all services are known, and all connections between them established at boot time by the root server. This is desirable when building a very secure system --- it allows infoflow analysis of who can talk to what, and it's guaranteed that information flows cannot be changed (in terms of which components can talk to each other) while the system is running. If you want to build a more dynamic system, you're right: you'd need some kind of directory service that allows components to register what they can do. That's out of scope for the microkernel, but is needed as part of a complete dynamic system. -- Dr Peter Chubb Tel: +61 2 9490 5852 http://ts.data61.csiro.au/ Trustworthy Systems Group Data61 (formerly NICTA)