Extreme Programming (XP):- A software development approach which assists better software standard and responsiveness to modify customer requirements.
Being a part of agile software approach, it encourage frequent delivery. Development circle/pattern which are very short, sometimes 2 weeks, plan to better productivity and customer satisfaction at the same time.
Pair Programming:- Work items are created by sets of individuals working jointly. Pairs change frequently whilst the responsibility stays with the owner. Programming in sets or doing large code review, unit testing of all code.
A flat administration construct, simple and clear code, required modification in the user's specification as time passes and the problem is better recognize, and frequent conversation with the customer, programmers and testers leads to a value for money to the customer.
Test Driven Development:- TDD marks this technique in a way that, test cases and test cases are written before the coding begins.
Continuous Integration is an integral part of this technique/methodology. The whole system is develop and verified end-to-end several times a day. While new verifications/tests are made should pass, no formerly passing tests are accepted to break. System must be in a deploy-able state all times.