"A small word of warning: linux looks like a unix, but I implemented it from scratch, and with very little literature on how things 'should' be done."
...and with very little literature on how things 'should' be done."
I would not say that Tannenbaum's "Operating Systems: Design and Implementation" book has "very little literature on how things should be done".
Linus had a copy of MINIX, he had the source code, and he had the book. He studied everything very closely. He also used UNIX at his university, which, BTW, is the reason (or at least one of the reasons) he began writing Linux; he wanted UNIX at home (another stated reason is that he wanted to learn more about how the 386 worked).
The "flame war" between Linus and Tannenbaum is also quite interesting to read, but I suppose most of you have already done so. For you that hasn't, it's basically "monolithic design (Linux) vs. microkernel design (MINIX)" and is available here.
You know, we've been calling Linus our "benevolent dictator" for years. I don't think it ever really clicked for me that his middle name is "Benedict." "Benevolent dictator? Why, that's his middle name!" *chuckle*
Program Intellivision and play Space Patrol!
Unix was coded Worse Is Better style anyway :D