Refactoring is a controlled technique for improving the design of an| martinfowler.com
Unit Tests are focused on small parts of a code-base, defined in regular programming tools, and fast. There is disagreement on whether units should be solitary or sociable.| martinfowler.com
Technical Debt is a metaphor for the consequences of cruft. You either have to accept a drag on further features (paying interest) or fix the software (paying the principal)| martinfowler.com
Every developer integrates their work into mainline at least every day.| martinfowler.com