James Britt wrote:

> 
> Does 1.6 have to be uninstalled before installing 1.8, on OS X?


No. When compiling and installing from source on OSX, ruby installs it's 
  binary into /usr/bin/ruby18 in which you have to rename it to 
/usr/bin/ruby. Because /usr/bin/ruby still is the 1.6 binary.

The lib files get installed into /usr/local/lib/ruby/ with 
subdirectories 1.8/ and site_ruby/

I dont even have a /usr/local/lib/ruby/1.6 directory anymore. I didn't 
intentionally delete it. Perhaps 'make install' did it for me. I'm 
running OSX 10.3, everything is factory install except for compiling 
ruby from source and installing wxRuby from Curt Hibb's one-click installer.

Zach