More important than the acronym is the effort itself. XINU is a really interesting project and probably the second OS I was introduced to outside of the POSIXy neighbourhood. It differs from a lot of other projects in that its goals (to my understanding) were very different to the usual approach toward providing POSIX compliance or a platform intended to support layering POSIX on top of a base architecture.
I picked up an old copy of the textbook and never read it. Maybe this is the kick I needed to pick up the newer edition and actually check it out in earnest!
When I first learned C I also read Lions' Notes on v6 Unix, and kind of saw what was going on, but the XINU book really drove home how kernels worked. The XINU book on internetworking was similarly great.
If you happen to read this, the courses at Purdue which are based around XINU seem to be CS354 and CS503. Some google-fu turns up lecture notes but I'll avoid linking them due to the fact that they don't seem to be openly distributed.
That may or may not be what you were after since the book is probably more detailed at to the point than the course notes would be.
I took the CS OS grad. course at Purdue last semester that taught OS principles using XINU. Overall, I think the OS is great. Used primarily for embedded systems (routers were the common example) it was simple, quite extensible and fun to learn.
Does anyone know if XINU is used in Purdue's undergrad OS classes these days? I went there and it was not mentioned even once (took OS around '04). Most of what we did was in Nachos[1]
XINU is used for CS354, the undergrad CS OS course (and has been for at least the last 2 years). A different OS is used for the undergrad ECE OS course; I think it may be Nachos, but I'm not sure.
See now this is my kind of acronym. Things like "gnu's not unix" are too arbitrary; you can replace the 'g' with anything and still get an acronym that works. XINU is nice, elegant, and unambiguous.
He is pointing out that leaving out "is" in "GNU is not Unix" is pretty lousy way to make an acronym (if that could be called acronym at all), as "is" is as much word as "not" or "Unix" are and omitting it is arbitrary. It isn't a preposition or something.
I picked up an old copy of the textbook and never read it. Maybe this is the kick I needed to pick up the newer edition and actually check it out in earnest!