Where RubyGems Puts Gems
- Each Gem has its own directory in
- `gem env gemdir` => /usr/local/lib/ruby/gems/1.8
- For example, Rake version 0.4.8 is in
- /usr/local/lib/ruby/gems/1.8/gems/rake-0.4.8
- require_gem searches the installed gems for a matching gem within
the version constraints
- and adds it to the $LOAD_PATH.