Ruby is pretty cool interpreted language and Rails is a pretty cool Web Framework. Ruby on Rails is pretty heavily used in the Internet for Web Development. Here is very good short introduction: GET_STARTED.
Installing Ruby 1.9 on Mac OS X
Installing Ruby 1.9.X on Debian Linux
GEM – Package Manager
Installing Web Framework Rails
Create a new Web App with Rails
Generate Model with Rails
Generate Migration with Rails
Robert Reiz 