Leopard comes with Rails, but I prefer to roll my own in an effort to keep my environment stable. As always Hivelogic has the goods:
- Installing Ruby, Rubygems, Rails, and Mongrel on Mac OS X 10.5 (Leopard)
- Special bonus: Why not install the latest copy of Subversion? This was written a while back, I followed the directions but went for version 1.4.6 rather than the one referenced on Hivelogic. You might get an error message when compiling, if so, follow the instructions in the comments.