Can I install two different Rails versions on the same computer (without using a virtual machine)? I want to switch back and forth easily between Rails 1.2.3 and Rails 2.0.2. I assume that if I try to gem-install a second version, there will still be only one rails file in my ruby\bin directory. How to resolve the two versions? I’m alternately using the command line, RadRails, and 3rd Rail.