The agile manifesto (which you can read at http://www.agilemanifesto.org) is the result of a meeting at the Snowbird ski resort in Utah in 2001. Prior to that date, the individual agile processes were referred to as lightweight. I think it was a good idea renaming it to agile because lightweight could have given the impression that it is easy to do and that heavy things were left out. Lightweight could also lead someone to believe that it was incomplete. Once you implement agile development practices, you will see that doing so can actually be difficult and that agile practices are not incomplete. The word agile, however, presents a challenge for the community. Nobody likes to admit that they are not agile, so some developers who call themselves agile are, in reality, not agile in our definition of the practices.
Despite any small misgivings about the name, all 17 participants at the ski resort defined the process and signed the manifesto, which was to become the measure of agility in the years to come. I remember the release of the manifesto, which immediately gave the industry a tangible definition of agile and ground rules for adding new ideas in the future. Still today, the manifesto provides clear direction and is used to discuss and compare agile methodologies. More important in my opinion, the manifesto provides one common roof for all agilists, whatever their favorite agile methodology might be. Here are the core values of the manifesto:
Individuals and interaction take precedence over processes and tools.
Working software takes precedence over comprehensive documentation.
Customer collaboration takes precedence over contract negotiation.
Responding to change takes precedence over following a plan
By the end of 2007, more than 4,700 professionals across the information technology (IT) industry had agreed to and signed the manifesto. Among the 17 authors of the manifesto were representatives from the Scrum, Extreme Programming, DSDM, and crystal clear methodologies.