This is an explanation of how to make a new, fresh Rails app of any released version of Rails.
First, generate a new rails app:
rails my_project
cd my_project
Find the release you want to use from
this list. There's a bunch of stuff in there - the Rails releases are prefixed with
rel_.
Then, ender this command to freeze Rails to the version you want. Remember to change the TAG= part (doh).
rake rails:freeze:edge TAG=rel_1-0-0
When this finishes, run the 'rails' command of the rails version you just froze to to have the rails app itself (the stuff in environment/ and so on) turned into the correct version.
ruby vendor/rails/railties/bin/rails .
Woot!