git clone https://github.com/rails/rails.git
move into that directory and install all the dependencies of rails cd rails bundle install cd ../
Now let’s create a new Rails 4 application ruby rails/railties/bin/rails new APPNAME –dev
All finished, now to run your Rails application as usual cd APPNAME bundle install bundle exec rails s —-
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For migrating your rails application from Rails 3 to Rails 4 contact [email protected]
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