Kent Beck is an American software engineer and the creator of extreme programming, a software development methodology that eschews rigid formal specification for a collaborative and iterative design process. Beck was one of the 17 original signatories of the Agile Manifesto, the founding document for agile software development. Extreme and Agile methods are closely associated with Test-Driven Development (TDD), of which Beck is perhaps the leading proponent.

Agile software development is the mindset for developing software that derives from values agreed upon by The Agile Alliance, a group of 17 software practitioners in 2001. As documented in their Manifesto for Agile Software Development the practitioners value:Individuals and interactions over processes and tools Working software over comprehensive documentation Customer collaboration over contract negotiation Responding to change over following a plan