Hi Markus,

Most of the installed libraries have used (for example)
/usr/local/lib/ruby/site_ruby/1.8/:
mylib.rb
mylib/

as you have shown.

Some of the more recent additions install just the single directory
/usr/local/lib/ruby/site_ruby/1.8/svg/:
svg.rb
{other files}

This last is from rubysvg-1.0.3 package.
An application that uses that library has this require:

require "svg/svg"

I prefer the latter, as this tends to keep all installed files under
one
directory, (the difference over the former is a small preference)

Best Regards,
Gerald