Dissatisfaction with heavyweight development approaches has lead to a proposal of agile methodologies. While heavyweight approaches are geared towards careful project planning, formalized quality assurance, and controlled and rigorous software development processes, the agile approaches focus on quick adaptation to change, and flexibility.

Today, there are a number of different agile methods available, such as Scrum, Crystal, Adaptive Software Development, Feature Driven Development, and extreme programming. Although different, they share the same principles. Some of them are: (1) individuals and interactions over processes and tools, (2) working code over comprehensive documentation, (3) customer collaboration over contract negotiation, and (4) responding to change over following a plan.

The proponents claim that agile methodologies lead to more effective and efficient development. The opponents, on the other hand, have stamped the agile approach as a "license to hack" or "cowboy", or "code-and-fix" method.