Looks like Ruby in Leopard has been give the Official treatment, with the latest stable version of Ruby ( plus important patches ) included with the base install. The latest RubyGem is included along with a bunch of useful gems like Rails, Mongrel, Hpricot and Capistrano.

There’s also an /etc/irbrc providing sensible defaults for IRB ( the interactive ruby interpreter ) which requires rubygems for you.

Ruby also comes with DTrace support which is also pretty cool. RubyCocoa is also included and should be fun to play with.

Check out this page for more info on Leopard’s new found Ruby Lovin’.