I see that when I install a gem, it gets installed under
/usr/local/lib/ruby/gems/1.8/gems/{gem-name}.

What does the 1.8 represent?
Is it the version of Ruby required to use the gem?
Depending on what other gems I install, could I also have a
/usr/local/lib/ruby/gems/1.6 directory?

--
R. Mark Volkmann
Partner, Object Computing, Inc.