How do UNIX linkers work.

How do UNIX linkers work with archive libraries, and why the order of objects and libraries on the link line matters. I originally wrote this article in 2001 in gnu.gcc.help. Here is a link to it. Since then, I had to refer many people to it, and so decided that a local copy (with a shorter URL) is in order. Here it is [slightly edited for clarity on 2006-01-10]: "Robert Kraus" <robkra@gmx.net> wr