Agile Software Development is an umbrella term for a set of methods and practices based on the values and principles expressed in the Agile Manifesto.
Solutions evolve through collaboration between self-organizing, cross-functional teams utilizing the appropriate practices for their context.

• The satisfaction of the customer must be guaranteed throughout all the development process.
• Change is a key of the ASD, developers must be capable of changing and adapting to the customer’s needs.
• Deliver new releases frequently.
• A friendly environment must be present between business people and the devteam.
• Promote motivation among all individuals involved.
• In order to be efficient, the communication must be face-to-face.
• Progress is measured by stable and working releases.
• There must be sustainable development by keeping a constant pace between sponsors, developers and users.
• There is constant attention to provide technical excellence.
• Keep things simple.Period.
• The devteam must be sustainable and self-organizing.
• Everyone involved learns from their mistakes and move on.

As everything in this world, ASD was criticised. There was an anti-agile movement called the Dark Manifesto for ASD. You can read it here.

It was also heavily criticised by Aaron Gray because of the working environment of ASD, in this critic, the author establishes that people is not always willing to work, or the team might not be so motivated to work in a team, and rather prefer to work alone.  The biggest argument is that programming or coding is not measurable, because of the environment uncertainty.

Written by Miguel Cabral and Juan Pablo Ramírez