Unix - just another program

Unix#tex2html_wrap4628# Un?x is a relatively popular operating system. For real distributed programs (as opposed to servers like Novell) a multi-tasking system of some kind is essential. So is some protection system (c.f. threads and micro-kernels - how much?, how many levels?). There are now many applications ported to Un*x, just as there are for MS-D*S. The debate here is whether we need to emulate the operating system, or merely provide the system interface. For any real distributed applications (few) we probably need the system semantics. Most applications run on a single system, so the interface alone may be sufficient.