Rails 3 - Developing simple app in few minutes

Installing rails 3 - Refer this post for install instructions

1. Create a application call "demo"

$ rails new demo
      create
      create  README
      create  Rakefile
      create  config.ru
      create  .gitignore
      create  Gemfile
      create  app
      create  app/assets/images/rails.png
      create  app/assets/javascripts/application.js
      create  app/assets/stylesheets/application.css
      create  app/controllers/application_controller.rb
      create  app/helpers/application_helper.rb
      create  app/mailers
      create  app/models
      create  app/views/layouts/application.html.erb
      create  app/mailers/.gitkeep
      create  app/models/.gitkeep
      create  config
      create  config/routes.rb
      create  config/application.rb
      create  config/environment.rb
      create  config/environments
      create  config/environments/development.rb
      create  config/environments/production.rb
      create  config/environments/test.rb
      create  config/initializers
      create  config/initializers/backtrace_silencers.rb
      create  config/initializers/inflections.rb
      create  config/initializers/mime_types.rb
      create  config/initializers/secret_token.rb
      create  config/initializers/session_store.rb
      create  config/initializers/wrap_parameters.rb
      create  config/locales
      create  config/locales/en.yml
      create  config/boot.rb
      create  config/database.yml
      create  db
      create  db/seeds.rb
      create  doc
      create  doc/README_FOR_APP
      create  lib
      create  lib/tasks
      create  lib/tasks/.gitkeep
      create  lib/assets
      create  lib/assets/.gitkeep
      create  log
      create  log/.gitkeep
      create  public
      create  public/404.html
      create  public/422.html
      create  public/500.html
      create  public/favicon.ico
      create  public/index.html
      create  public/robots.txt
      create  script
      create  script/rails
      create  test/fixtures
      create  test/fixtures/.gitkeep
      create  test/functional
      create  test/functional/.gitkeep
      create  test/integration
      create  test/integration/.gitkeep
      create  test/unit
      create  test/unit/.gitkeep
      create  test/performance/browsing_test.rb
      create  test/test_helper.rb
      create  tmp/cache
      create  tmp/cache/assets
      create  vendor/assets/stylesheets
      create  vendor/assets/stylesheets/.gitkeep
      create  vendor/plugins
      create  vendor/plugins/.gitkeep
         run  bundle install
Fetching source index for http://rubygems.org/
Using rake (0.9.2.2)
Using multi_json (1.0.4)
Using activesupport (3.1.3)
Using builder (3.0.0)
Using i18n (0.6.0)
Using activemodel (3.1.3)
Using erubis (2.7.0)
Using rack (1.3.6)
Using rack-cache (1.1)
Using rack-mount (0.8.3)
Using rack-test (0.6.1)
Using hike (1.2.1)
Using tilt (1.3.3)
Using sprockets (2.0.3)
Using actionpack (3.1.3)
Using mime-types (1.17.2)
Using polyglot (0.3.3)
Using treetop (1.4.10)
Using mail (2.3.0)
Using actionmailer (3.1.3)
Using arel (2.2.1)
Using tzinfo (0.3.31)
Using activerecord (3.1.3)
Using activeresource (3.1.3)
Using ansi (1.4.1)
Using bundler (1.0.21)
Using coffee-script-source (1.2.0)
Using execjs (1.2.13)
Using coffee-script (2.2.0)
Using rack-ssl (1.3.2)
Using json (1.6.4)
Using rdoc (3.12)
Using thor (0.14.6)
Using railties (3.1.3)
Using coffee-rails (3.1.1)
Using jquery-rails (1.0.19)
Using rails (3.1.3)
Using sass (3.1.12)
Using sass-rails (3.1.5)
Using sqlite3 (1.3.5)
Using turn (0.8.2)
Using uglifier (1.2.1)
Your bundle is complete! Use `bundle show [gemname]` to see where a bundled gem is installed.

2. Go to app folder

$ cd demo

3. Generate a controller called Index with method init

$ rails generate controller Index init
      create  app/controllers/index_controller.rb
       route  get "index/init"
      invoke  erb
      create    app/views/index
      create    app/views/index/init.html.erb
      invoke  test_unit
      create    test/functional/index_controller_test.rb
      invoke  helper
      create    app/helpers/index_helper.rb
      invoke    test_unit
      create      test/unit/helpers/index_helper_test.rb
      invoke  assets
      invoke    coffee
      create      app/assets/javascripts/index.js.coffee
      invoke    scss
      create      app/assets/stylesheets/index.css.scss

4. Start WEBrick server

$ rails server

=> Booting WEBrick

=> Rails 3.1.3 application starting in development on http://0.0.0.0:3000

=> Call with -d to detach

=> Ctrl-C to shutdown server

[2012-01-04 23:24:05] INFO  WEBrick 1.3.1

[2012-01-04 23:24:05] INFO  ruby 1.9.2 (2011-07-09) [i686-linux]

[2012-01-04 23:24:05] INFO  WEBrick::HTTPServer#start: pid=3220 port=3000

Now app can be accessible by browser. Further you can add/modify controller, view and functionality

http://localhost:3000/index/init 

This is very simple app.it may take few mins.