I just downloaded Foxtails (the FXRuby extensions), and upon running the
install scripts I was surprised to see that a bunch of the ruby files that
came with it had been copied over into my ruby/lib/site_ruby/1.8 directory.

Is there a reason why installing libraries needs to make changes to the
directory in which ruby itself is installed? I would have expected the
installation to instead make additions to the path in $: instead.

How does 'require', $:, and installation of new libraries work? (Hyperlink
welcome; I did not find what I needed in pickaxe).

Thanks ...