Testing
- Unit tests
 - Integration tests
 - Acceptance tests
 
TDD and BDD
- RSpec
 - Cucumber
 
Acceptance Testing Tools
- Capybara https://github.com/jnicklas/capybara
 - Selenium http://www.seleniumhq.org
 - Poltergeist https://github.com/teampoltergeist/poltergeist
 
Automatic Testing
- 
autotest
 - 
guard
 
Continuous Integration
when new is pushed to the repository, the CI downloads the new code, run the test suite on remote server. testing is continuously integrated with you code repository.
- Travis CI
 - Circle CI
 - Jenkins CI
 - gitlab
 
Other Tools
- shoulda-matchers
 - e
 - timecop
 - webmock
 - vcr
 - spork