Check out RailsLive CD, it has all the essential tools for Rails
development on Linux. You have two options:
1. Boot RailsLiveCD from a CD.
2. Install VM ware player and run the RailsLiveCD.
I got the option two working after some struggle and help from the
creator of that product. Here is link:
Cool thing is that you can save all your work on a flash drive and
work on any machine.