>I can't seem to find the errors (StandardError and it's subclasses) in the
    >library reference. Anyone knows why they are not in there?

They're in a section in another part of the book. The system errors
(Errno::xxxx) are platform specific and take their name from the
underlying error, such as Errno::EBADF.  You can print out all
the exceptions classes for your platform with:

ObjectSpace.each_object(Class) {|x| puts x if x <= Exception }

    >BTW, why is the library reference copyrighted to Addison Wesley? Because
    >it will be in the book? 

Dave and I wrote it for the book, and AWL owns copyright on the book
material.  They've agreed to let us post (at a minimum) the reference
section.

    >Any problems with downloading local copy?

You already have :-).  I'm not a lawyer, but by viewing it on
the web it seems you've already downloaded a copy to your machine.
I don't think saving it off for personal use would be a problem.

/\ndy