In raising the question about whether a specific programming language is agile I want to avoid exploring what makes a language agile, or comparing PHP with other languages. The intention here is not to associate PHP to agile as a natural relationship, as much as to try and understand if we can find the ingredients in the PHP world, for creating an agile environment.
Agile in the context of software development is no more than a set of principles and values as they were identified by a group of people (The 17 Agile Manifesto's signatories) who were then developing software in ways that somehow contrasted with the traditional processes. They had introduced into their development, practices which focused on delivering early and often, favoring constant feedback and change, low overhead, reduced ceremony and flat hierarchy.