Github
Alternative: Bitbucket, git (private server)
None
Alternative: Pivotal Tracker, client system
2nd git repo
Alternative: Basecamp
Slack
Alternative: Campfire
Pivotal Tracker with Lighthouse
Codeship
Alternative: Travis CI, tddium, and Jenkins
Bugsnag, Logentries, Papertrail
Alternative: Airbrake, Errbit, Exception Notifier
New Relic
Alternative: Librato
New Relic
Alternative: Pingdom
Google Analytics
Alternative: gaug.es, Sumall
Rails 4
Alternative: Rails API
Spree
PostgreSQL 9.x
Redis
Alternative: MongoDB
Slim
Alternative: HAML, ERB
Simple Form
Alternative: Formtastic
SASS/Compass
Alternative: CSS
jQuery
Alternative: plain js with CoffeeScript
None, what's built into Rails 4 is good enough.
Twitter Bootstrap
Alternative: Foundation, Compass with Susy and UI Packs
None
RSpec
Alternative: Test::Unit
Jasmine
Alternative: CasperJS, QUnit
Capybara with Poltergeist
Alternative: PhantomJS with CasperJS, Capybara-webkit
FactoryGirl, Faraday, Shoulda
Alternative: VCR, Typhoeus, MockSMTP
Codeship
Alternative: Docker, Dokku, Capistrano if not on Heroku
Bundler
Rails 4 Asset Pipeline
Alternative: Broccoli
Devise, Pundit, OmniAuth
Alternative: CanCanCan
Carrierwave
Alternative: Paperclip
ActiveMerchant
Alternative: Spreedly or hand-rolled code
Heroku
Alternative: DigitalOcean, AppFog, AWS Elastic Beanstalk
Puma
Mandrill
Alternative: Google Apps
None
Alternative: Docker, Puppet, Chef
TBD
Alternative: Heroku PG Backups, S3cmd
Braintree with transparent redirect
Alternative: Spreedly, Stripe