The Manifesto for Agile Development declares four preferences and twelve principles.

It may be a coincidence, but the principles seem to nest comfortably under the preferences.

The four preferences

The twelve principles

Individual and Interactions
- Build projects around motivated individuals. Give them the environment and support they need, and trust them to get the job done.
- The most efficient and effective method of conveying information to-and-within a development team is face-to-face conversation.
- The best architectures, requirements, and designs emerge from self-organizing teams.
Working Software
- Working software is the primary measure of progress.
- Continuous attention to technical excellence and good design enhances agility.
- Simplicity -- the art of maximizing the amount of work not done – is essential.
Customer Collaboration
- Our highest priority is to satisfy the customer through early and continuous delivery of valuable software.
- Deliver working software frequently, from a couple of weeks to a couple of months, with a preference to the shorter timescale.
- Business people and developers must work together daily throughout the project.
Responding to Change
- Welcome changing requirements, even late in development. Agile processes harness change for the customer's competitive advantage.
- Agile processes promote sustainable development. The sponsors, developers, and users should be able to maintain a constant pace indefinitely.
- At regular intervals, the team reflects on how to become more effective, then tunes and adjusts its behavior accordingly.